Abstract
Online platforms make it possible for physicians to share online information with the public, however, few studies have explored the underlying mechanism of physicians’ sharing of paid health information. Drawing on motivation theory, this study developed a theoretical framework to explore the effects of extrinsic motivation, enjoyment, and professional motivation on the sharing of paid information, as well as the contingent role of income ratio (online to offline) and online reputation. The model was tested with both objective and subjective data, which contain responses from 298 physicians. The results show that extrinsic motivation, enjoyment, and professional motivation play significant roles in inducing physicians to share paid information. Furthermore, income ratio can moderate the effects of motives on paid information sharing. Besides, the effect of professional motivation can be more effective in certain situations (low-level income ratio or high online reputation). This study contributes to the literature on knowledge sharing, online health behaviour, and motivation theory, and provides implications for practitioners.
Keywords
1. Introduction
In recent years, the development of the global economy has placed a huge demand on limited health resources. Like most developing countries, China has long suffered from a serious shortage of health resources and their imbalanced allocation [1]. With the improvement of Internet-based technologies, online health communities have emerged. These communities offer platforms for people across the country on which, physicians can provide online diagnosis and treatment information, and other online health services to remote patients [2]. The online health communities move offline health services online, ensuring that patient-physician interaction is not constrained by time or space and that patients and their relatives have more access to health information [3]. This new model of health service can optimise the allocation of health resources and compensate for its imbalance [4].
Physicians participate in online health communities to share free or paid health information [5]. Empirical studies have extensively explored the role of monetary incentives in physicians’ sharing behaviour [6,7], arguing that this extrinsic motivation is the major driving factor. Some studies propose other motives, such as concern for face and reputation [8] and offline status [9]. Therefore, current research has treated physicians as general online community users and seldom mentioned their special features. Physicians are similar to teachers or lawyers, as a group with professional knowledge, their sharing behaviour will be greatly motivated by professional motivation [5,10]. Also, compared to general online communities, the contributing users in health communities are physicians, who have their work schedule in hospitals and use free time to share online [3]. All these may make online health communities different from general communities. However, research into the unique mechanism of physicians’ online sharing behaviour from a holistic perspective is lacking. As a recent study by Zhang et al. [5] has extensively explored physicians’ sharing of free information, this study is designed to explain the motives of their sharing of paid information. Accordingly, we propose our first research question: What is the underlying mechanism that drives physicians to share paid health information?
According to the motivation theory, there are two major types of motives for human behaviour: intrinsic and extrinsic [11]. This study uses this theory to provide a holistic explanation of physicians’ sharing of paid health information. Consistent with previous literature, it proposes that monetary incentive is the major motive for physicians to share paid health information [12,13]. On most online platforms, physicians may benefit monetarily by sharing their professional knowledge [7,14]. Intrinsic motivation refers to engaging certain behaviours for inherent rewards [15], which can also be a key predictor of physicians’ online sharing behaviour. According to the motivation literature, intrinsic motivation can be enjoyment-based or obligation-based [11]. Individuals tend to enjoy helping others in both online and offline contexts [16]. We thus draw on perceived enjoyment to measure physicians’ enjoyment-based intrinsic motivation [17,18,19]. To measure obligation-based intrinsic motivation, this study draws on physicians’ unique features to incorporate professional motivation into motivation theory. Physicians form a professional and highly educated group that possesses professional knowledge others do not [20]. Because sharing paid online health information is a professional service provided by physicians that is similar to their offline work in hospitals, we propose that professional motivation can also be a key determinant of their sharing of paid health information [21]. Professional motivation is the psychological process for driving professionals to pursue their goals and obligations [22]. It has been used to study the offline behaviour of teachers and lawyers but is seldom mentioned in the online context or motivation theory. Future investigation of physicians’ professional motivation is of great importance for better understanding their online knowledge sharing and motivation. Accordingly, the second research question leading this study is: Does professional motivation drive physicians to share paid health information in online health communities?
To further investigate the underlying mechanism of physicians’ online sharing behaviour, this study also explores whether the effects of motivations are contingent on the ratio of online to offline income (we name it as income ratio below) and online reputation. According to the previous studies, physicians’ online sharing behaviour can be affected by their properties (the individual characteristics that can differentiate them from others) because their properties may shape their responses to the benefits of participating in online health communities [1,13]. Even though the effects of online income (from online platforms) [6,23] and offline income [7] on their sharing behaviour have been extensively explored, few studies have incorporated both online and offline income in exploring their information sharing, thus no overall picture exists of how physicians behave differently in online and offline situations. Conversely, empirical studies have shown that when indicators of a physicians’ offline reputation, such as hospital levels and departmental grades, are recognised online, physicians opt to share more information in online health communities [24]. In other fields, such as quality certification, the International Organization for Standardization certification has been found to lead to better performance by organisations [25]. However, little attention has been given to the influence of physicians’ reputations in online communities on their sharing of health information. A close investigation of the contingent roles of income ratio and online reputation will improve the current understanding of how physicians’ motives determine their paid information-sharing behaviour in different situations. Accordingly, we propose the third research question: Whether the effectiveness of physicians’ motivation to share paid health information is contingent on their income ratio and online reputation?
Drawing on the literature on online health information sharing, motivation theory, income ratio, and reputation, a theoretical model associated with six hypotheses was developed. To test the hypotheses, a panel data set from an online health community that enables physicians to provide paid health information was constructed. This study contributes to the extant literature in several aspects. First, this study is one of the first to identify physicians’ sharing of paid health information and explain the underlying mechanism of the motivations. Second, even though the role of physicians’ properties has been widely explored in the online context, less research attention has been paid to the interplay between their online and offline characteristics. By specifically exploring the contingent roles of the income ratio and online reputation, this study increases understanding of the effectiveness of the motives behind professional groups’ sharing of paid information. Third, this study contributes to motivation theory by incorporating professional motivation to fit professional groups in the knowledge sharing literature. This study also provides insightful implications for practitioners.
The whole work is organised as follows. The next section reviews the related studies on the topic or theory and the third section proposes the research model and associated hypotheses. A research methodology section, including data collection and analyses, is then presented. The fifth section discusses the key findings, implications, and limitations and the last section concludes the whole work.
2. Theoretical backgrounds
2.1. Online health communities
Online communities are virtual platforms whose evolution is closely related to developments in the worldwide Internet revolution [26]. Online communities are open collectives of dispersed members who share common interests and collective welfare and exchange information [27]. As the number of patients with complex health care needs rises dramatically [28] and exceeds the number of local physicians who can meet their needs, online health communities have developed as new services platforms to share health information, discuss disease experiences, and deliver health services [4,29]. Such communities gather a group of patients, a group of physicians, or a mixture of the two to interact online [30]. These communities can be used to share disease experience, health knowledge, and disease-specific information, which can engage and empower patients in their health management and bridge geographical distance [31]. It has been widely verified that online health communities can benefit patient outcomes [32], physician income [1,5], and the reduction of health disparities [4,29]. This study focuses on the communities that enable physicians to provide paid health information through consultation services.
Extensive studies have explored the determinants of user participation in online health communities from various perspectives in terms of free and paid information sharing. 1 Because physician users are the main information contributors, much research attention has been paid to their motivations [5]. At first, scholars focused on examining the motivations for physicians’ sharing of health information, proposing different motives, such as altruism and personal gain [12]. According to motivation theory, these motives can be further categorised into intrinsic and extrinsic motivation [11]. Following this line, later studies explored different intrinsic and extrinsic motivations inducing physicians’ sharing of health information. Table A1 in Appendix A summarises these studies. Because the effectiveness of motivations may vary among individuals according to their knowledge, skills, and incomes [33], we also reviewed the physician properties in these motivation studies.
From the review, it can be concluded that three gaps exist in the current literature. First, current studies on physicians’ sharing of paid health information from a holistic perspective are insufficient. Although a limited number of empirical works have explored physicians’ paid health information-sharing behaviour [6,7], they focused mainly on the effects of monetary incentives and neglected other motivations. Studying the motives behind physicians’ sharing of paid health information from a holistic perspective is beneficial for understanding physicians’ online sharing behaviour.
Second, although numerous studies have examined the motivations for physicians’ sharing of paid or free (voluntary) health information, few have identified the specific motivation mechanism of paid information sharing in the online context. Despite many efforts made to reveal physicians’ key motivations in online health communities, such as intrinsic motivation (e.g. enjoyment, altruism, reputation, and reciprocity) and extrinsic motivation (e.g. material incentives, reciprocity, and reputation), little research attention has been paid to physicians’ special motivation that considers physicians a specific and professional group. Only two studies have involved physicians’ special motivation: Guo et al. [1] use professional capital to manifest the status capital that influences physicians’ online sharing behaviour, and Zhang et al. [5] draw on professional motivation to study physicians’ sharing of free information. They have not reconciled these special motivations into motivation theory to provide a holistic explanation of the underlying motives for physicians’ sharing of paid health information.
Third, little research attention has been paid to physicians’ properties from both the online and offline contexts. Switching from offline to online, physicians’ online sharing behaviour can be affected by two factors: offline context and online context. Some studies investigating physicians’ motivations for online knowledge sharing have addressed properties such as online reputation [23,34], hospital-level [35], professional status [36], offline status [9,36], professional title [37], and online expertise [5]. Few have addressed properties from both online and offline contexts.
To narrow the aforementioned gaps, this study develops a framework to explore the motivations for physicians’ sharing of paid health information in online health communities, and further examines whether the effectiveness of physicians’ motivations is contingent on their properties. Next, we review the literature on motivation theory and the physician properties in this study.
2.2. Motivation theory
Motivation is a mental state or condition that determines human behaviours [20,38]. According to motivation theory, motivations can be categorised as intrinsic or extrinsic [11]. Intrinsic motivation refers to individuals conducting certain behaviours because they are inherently interesting or enjoyable, whereas extrinsic motivation refers to individuals conducting certain behaviours because of the direct and indirect outcomes of the behaviours [14,34].
As reviewed in Table A1, previous studies have indicated that extrinsic and intrinsic motivation can induce physicians to share health information in different online contexts. In the contexts in which physicians can obtain incentives from sharing health information, extrinsic motivation is the major motive [6,7,23]. Extrinsic motivation is characterised as a strong focus on reward contingencies; some paid service communities have a profit motive and offer monetary compensation to information providers for their time and efforts [14,33]. Thus, to explore the motives behind physicians’ sharing of paid health information, this study also draws on extrinsic motivation as the major motive.
As can be concluded from Table A1, different types of intrinsic motivation, such as knowledge, self-efficacy, enjoyment, curiosity, moral obligation, altruism, and empathy have also been found to induce physicians to share voluntary health information in online communities [39,40]. Intrinsic motivation can also influence physicians’ decision-making on sharing paid health information because, in addition, monetary incentives, physicians can take an interest in or perceive enjoyment from sharing health information in online communities to help patients [12,35]. To gain a better understanding of intrinsic motivation, Lindenberg [41] divided it into enjoyment-based (i.e. the drive to become satisfied by conducting a certain behaviour) and obligation-based (i.e. the drive to uphold certain values and ethics by conducting a certain behaviour). Drawing on this taxonomy, this study proposes to manifest physicians’ intrinsic motivation by enjoyment and professional motivation. Enjoyment is regarded as an enjoyment-based intrinsic motivation that is defined as physicians experiencing inherent satisfaction (e.g. having fun, feeling happy, and personally gratified) from helping patients by sharing their health knowledge, rather than being driven by monetary incentives [42].
For the first time, this study defines professional motivation as an obligation-based intrinsic motivation. It refers to the psychological process occurring in the professional groups when realising their goals and tasks in workplaces [22]. Professional motivation is a type of motivation that applies to special professionals who possess irreplaceable expertise and work ethics, such as physicians, teachers, and lawyers. In online health communities, the professional obligation of physicians will guide enhance their self-satisfaction and sense of accomplishment as a physician [5]. Several previous studies have demonstrated that professional motivation contributes to career development [43], efficiency promotion [12], better performance [20], professional satisfaction [44], and social psychological adaptation [35]. However, little research has explored the role of professional motivation of physicians in online health communities. Zhang et al. [5] studied the effect of professional motivation on physicians’ sharing of free information, but they did not combine it with motivation theory.
Therefore, this study expands the motivation theory by incorporating professional motivation as a subdimension of intrinsic motivation to provide a holistic view of the motives behind physicians’ sharing of paid health information. By doing so, this study can provide an overall perspective to understand why physicians share paid health information.
2.3. Physician properties
This study further investigates whether the motives behind physicians’ sharing behaviour have different effects according to physicians’ properties. Specifically, we will discuss two aspects of properties, those related to income and those related to reputation, because income is argued to be the major motive for sharing paid health information and reputation indicates the quality of physicians’ expertise [45].
In many research areas, monetary incomes are increasingly used as an approach to improving work performance [46]. Studies in online health communities have also confirmed that monetary incentives can promote physicians’ sharing of online information [5,6,9,34], and that for physicians working in hospitals, monetary incentives have a variety of effects depending on the physicians’ characteristics [47]. Many boundary conditions related to their online income [1,5] and offline income [7,9] have been identified to explore physician properties. Even though these studies have explained how physicians respond to the incentives for sharing health information among physician groups with different online or offline incomes, they fail to ascertain whether physicians with different ratios of online and offline incomes value the further incentives differently. Therefore, this study is one of the first attempts to use both online and offline income to explore the different motives of physicians for their sharing of paid health information.
In the health care system in China, physicians’ professional titles and affiliations in hospitals are usually indicators of their service reputation, representing their professional capabilities and work experience in the offline context [3]. The offline reputation is generally measured using their hospital rank and professional titles, and extensive empirical studies have explored the role of offline reputation in online communities. For instance, establishing a reputation and shame policy can induce physicians to provide higher quality service to avoid reputational damage [48]. However, few studies have explored the role of online reputation in physicians’ online paid information sharing.
The online reputation reflects the quality of information, timeliness of sharing, and attitude towards patients in physicians’ sharing of paid information to specific patients to address their health concerns [49]. Physicians’ online reputations can directly help them to attract more patients [50] and can increase their sharing of health information [24,35]. However, the indirect effects of online reputation on physicians, such as whether it shapes the relationship between physicians’ motives and their sharing behaviour, have seldom been explored [8]. Furthermore, even achieving online reputation can also be a part of extrinsic motivation of physicians to work online, as the reputation system is created by the patients and shown on physicians’ homepage, online reputation can also be treated as one significant physician properties. Thus, this study stratifies physicians according to their different online reputations and explores whether the motives for physicians’ sharing of paid health information have different effects in online health communities. To sum up, this study regards income ratio and online reputation as two significant physicians’ properties in explaining whether physicians among different groups are motivated differently to share paid health information.
3. Research model
This study mainly explores the motives for physicians’ sharing of paid health information in online health communities from a motivation perspective and considers the contingent role of physician properties, that is, income ratio and online reputation. Accordingly, we propose a conceptual model associated with six hypotheses. Figure 1 presents the model.

Theoretical research model.
3.1. Relationship between motivations and paid information sharing
Extrinsic motivations, such as financial incentives and income promotion, are increasingly used to improve user contribution in many fields. Some paid service communities can make a profit from the knowledge seekers and provide monetary compensation to knowledge providers [13,33]. In online health communities, in-service physicians own the expertise and clinical experience in health care, and they can benefit directly or indirectly (through virtual gifts) from sharing paid health information through answering patients’ inquiries.
The monetary rewards for answering patients’ inquiries indicate, to a certain extent, the recognition of the importance of the health information provided by the physicians and represent the patients’ respect and gratitude [51]. This enables physicians to be clearly aware of the rewards of sharing health information. Monetary incentives as visible and direct compensation for their time and effort can have a direct impact on physicians’ sharing of paid health information and can motivate them to contribute more to the communities. We propose that
Intrinsic motivation is the motivation of personal interest in an activity and inherent satisfaction [6]. Enjoyment, as a pure intrinsic motivation, occurs when individuals choose to do something because it is fun and enjoyable in essence [34]. In the context of online health communities, the degree of fun and pleasure can affect physicians’ sharing of paid health information. Online health communities replicate offline health scenarios in the network environment, and physicians use their knowledge and long-term working experience to offer online paid consulting services to provide patients with more information about their diseases and treatment [6]. In doing so, physicians can gain a sense of being needed, realise their own value, and feel enjoyment to contribute in the online communities [17,52]. The enjoyment they derive from helping patients will further motivate them to share more health information [53]. Thus, we propose that
Professional motivation, a typical intrinsic motivation, refers to the psychological processes driving physicians to achieve their goals and tasks in their area of expertise [22]. In online health communities, the professional motivation of physicians can be an important factor influencing their sharing of paid information [14,18].
Professional motivation stems in part from occupational obligation, and as professionals possessing medical knowledge, physicians naturally have a functional obligation to help patients manage their disease and illness [54]. The sense of fulfilment and professional competence derives from career development and recognition by patients, and physicians tend to obtain patient satisfaction and gratitude by providing guidance [6,52,53]. Therefore, professional motivation can induce physicians to use their own expertise to provide patients with paid health information and to obtain social acceptance and value recognition. In addition, professional motivation renders physicians willing to challenge themselves to address patients’ inquiries and enhance their skills [53]. When encountering patients’ inquiries, physicians will be self-motivated to address them with their professional knowledge by sharing health information. Previous studies have also indicated that professional motivation is positively related to efficient career promotion and performance by inducing individuals to address challenges [44]. Accordingly, we propose that
3.2. The moderating effect of income ratio
Physician income can be divided into two parts: online income and offline income. Research on online physician behaviour finds that income from offline hospitals will affect their response to the incentives provided by online communities [53,55]. Furthermore, the greater the ratio of online to offline income, the greater the proportion of the income earned by physicians from the online health communities in their overall income [13]. The greater their online income, the less attention physicians will pay to information sharing in online health communities because they have already obtained online monetary rewards. Because extrinsic motivation is largely manifested in the monetary incentives from online sharing and physicians with a higher income ratio are less sensitive to these incentives, they will pay less attention to their extrinsic motivation induced by online income. We propose that
Previous studies have indicated that monetary incentives restrain the effect of intrinsic motivation on human behaviour, this phenomenon is called the crowding-out effect [56]. Empirical studies have also verified that online incentives undermine online users’ intrinsic motivation (e.g. enjoyment) in online contexts, thus exerting crowding-out effects [57]. Physicians with a high-income ratio have a higher percentage of income from the online health communities than those with a lower income ratio. This also means they have a high level of extrinsic motivation to increase income from online communities and a low level of enjoyment from sharing behaviour. However, if some physicians can still enjoy sharing, this means they still inherently like sharing paid information to help patients and are less extrinsically driven, and thus the effect of enjoyment among these physicians will be enhanced. A higher-income ratio leads to a stronger relationship between enjoyment and paid health information sharing. We hypothesise that
As mentioned previously, physicians with a high-income ratio have a higher percentage of income from online communities. Thus, when participating in online communities and deciding whether to share health information to gain rewards, these physicians will be more incentive-driven than those with lower income ratios [6,7], and therefore, they will care less about professional and ethical obligations to help patients in the online health communities. Then their reliance on professional motivation to share online information will be weakened. Conversely, if physicians have a low-income ratio (most of their income is from their offline hospital work) and are still sharing online health information, they will rely more on their professional and ethical obligations to work on the online communities. Thus, their reliance on the professional motivation to share in the online communities will be strengthened. Therefore, we propose that
3.3. The moderating effect of online reputation
Physicians’ online reputation refers to the personal labels that physicians obtain in online health communities to indicate the certification of their sharing behaviour. Online reputation reflects their information-sharing experience, the quality of their knowledge sharing, and their attitude in the sharing process [49], which may affect their motives for sharing paid health information.
According to signal transmission theory, reputation affects patients’ choice of physician to a certain extent [58]. In addition, empirical studies have revealed that the online reputation of physicians can help them attract more online patients [45]. Increased patient numbers mean more opportunities for physicians to share paid information and acquire more rewards from online health communities. In this situation, physicians with a good online reputation will pay less attention to the monetary incentives and gradually move their focus to patient satisfaction and self-contribution to maintain the online reputation that they already have [49]. Thus, their reliance on monetary incentives to share paid health information will be weaker compared with those who have a poorer online reputation [3]. Therefore, we propose that
Online reputation is the patients’ perception of physicians in their sharing of health information. It is generated through patient feedback, such as ratings, evaluations, and voting [58]. Physicians with a good online reputation indicate that they obtain more positive patient evaluations than those with a poorer reputation. The positive patient evaluations will lead them to inherently like sharing information with patients to help them. Therefore, when they feel enjoyment from helping patients, physicians with a good online reputation will be highly motivated to share more health information [19]. In contrast, those with a poor online reputation will rely more on incentives than enjoyment. Therefore, we propose that
Online reputation may also moderate the relationship between professional motivation and paid information sharing. Professional motivation for physicians to share information in online communities involves raising awareness of their obligations and tasks and increasing training opportunities and professional skills [59]. Their reputation reflects the long-term stability and quality of health information the physicians have shared with patients, which to a certain extent indicates their professional skills and obligation [5,49]. Physicians with a good online reputation will be more likely to be motivated by maintaining and expanding their online reputation and pay more attention to improving their professional skills through sharing paid health information. We propose that
4. Research methodology
4.1. Data collection
An online survey was conducted to test the above hypotheses, for two reasons: (1) our research topic, paid health information sharing, is about physicians using online health communities; and (2) in the context of online health communities, it is more convenient to contact physicians through an online survey. Therefore, samples in the online survey can be representative to a certain degree. We drew on a mobile platform, the AliHealth app in China, as our research context. This app provides a platform for physicians to share their professional knowledge and information with patients across the country. By the end of December 2019, the platform was used by about 27,000 physicians and 0.16 billion active patients. 2 The platform provides two sections for each physician: a home page presenting their basic information such as offline hospital, professional title, and sharing experience (labelled high-quality service), and a community section where physicians are able to share paid health information by replying to patients’ inquiries. Figure 2 shows examples of the two sections.

Examples of online physicians’ home pages and information sharing.
The survey questionnaire comprised two dimensions. The first section covered physicians’ usage of the AliHealth app and their basic information such as demographic information, approximate online income, and offline income, and the other section involved physicians’ responses to the measures of the theoretical constructs. To ensure the reliability and validity of the measures, most constructs were measured by the established scales in the existing literature. Based on interviews with several online physicians and the literature on system usage [60], we used daily login frequency, weekly usage duration, and the number of replies to each patient inquiry to manifest their paid information-sharing behaviour in online health communities. The measures of professional motivation [53,61], enjoyment, and extrinsic motivation [53] were adopted from previous literature and adapted to our research setting. The measures were first developed in English and then translated into Chinese. To reduce the common method bias in the survey-based data, we further drew on the ‘high-quality service’ label to measure the online reputation of each physician. Please refer to Appendix B for the measures in the survey.
A web survey’s response rate is a critical measure of data quality. According to Liu and Wronski [62], survey length and question difficulty show a significant negative impact on response rate. In order to improve the response rate, the online survey only contains 15 closed-ended questions whose lengths are all less than 25 characters and merely takes respondents 5 min to finish.
With the help of the platform, the online questionnaire was sent to the in-service physicians in the form of hyperlinks through internal social networks. By 6 May 2020, a total of 660 questionnaires had been collected. After removing those with incomplete items, repeated answers, unusual short-time responses, and outliers, 298 valid samples were used to test the research model. Twenty-seven provinces across China produced respondents, of which 61.22% were male and 38.78% were female. Moreover, 62.88% were under the age of 30, 25.26% were between 30 and 50 years old, and about 11.86% were over 50 years old.
Data from the questionnaire were used to measure extrinsic motivation, enjoyment, professional motivation, and sharing of paid health information in the online health community. Online reputation was measured with objective data from the platform that indicates ‘high-quality service’ ranging from 0 to 5. Offline and online income was first measured in the survey with interval numbers and then used to calculate income ratio (a higher ratio means more offline income or less online income). In addition, physicians’ demographic characteristics, such as age, gender, and hospital label, were used as control variables.
4.2. Measurement model
Smart partial least squares (PLS) was applied to measure the measurement model. Based on motivation theory, we drew on extrinsic motivation, enjoyment, and professional motivation as independent variables to predict physicians’ sharing of paid health information. Furthermore, income ratio and online reputation were identified as moderator variables. Because the theoretical constructs were measured by physicians according to their own perceptions, they may have varied in reliability and validity [63]. We further tested the reliability and validity of the measurement model. The results are shown in Tables 1 and 2.
Cross loadings.
ENJ: enjoyment; EXM: extrinsic motivation; PFM: professional motivation; SPHI: sharing of paid health information; ORP: online reputation; IRT: income ratio.
Boldface is used for values larger than 0.60.
Discriminant validity.
AVE: average variance extracted; CR: composite reliability; ENJ: enjoyment; EXM: extrinsic motivation; PFM: professional motivation; SPHI: sharing of paid health information; ORP: online reputation; IRT: income ratio.
The diagonal values are the square roots of AVEs.
Boldface is used for values larger than 0.60.
First, validity was assessed by investigating both convergent validity and discriminant validity. For convergent validity, items were required to load well on their target construct. Table 1 shows that the loadings of each item on its construct were larger than 0.60 (values in bold), indicating that convergent validity is good [64]. Discriminant validity was assessed through two approaches: (1) the items of each construct loaded more poorly on other constructs than itself (as shown in Table 1); and (2) the correlations of any two constructs were smaller than the square roots of their average variance extracts (AVEs) (as shown in Table 2). Thus, there was little validity concern in our measurement model [64].
Second, the reliability was further tested. Most of the Cronbach’s α values were greater than 0.70 and composite reliabilities were larger than 0.70, indicating that the research data have high reliability [64,65]. After deleting one item, Cronbach’s α did not change significantly, so all items should be retained, which further indicates that the reliability of the research data was relatively high.
Given that the correlations of some constructs were slightly high, multicollinearity may have been an issue that biased our results. We further measured the variance inflation factor values of the theoretical constructs (i.e. enjoyment, professional motivation, and extrinsic motivation), all of which were between 1.1 and 4.3, far below the threshold of 10 [66], indicating that collinearity is not an issue in this study.
4.3. Structural model
The structural model was then used to test the research model and associated hypotheses. To test the model with six moderating hypotheses, we adopted hierarchical regressions to estimate the results in three stages. Stage 1 focused on the effects of independent and control variables on sharing of paid health information, Stage 2 tested the moderating role of income ratio, and Stage 3 verified the moderating role of online reputation. Table 3 presents the results.
Result of hierarchical regressions.
ENJ: enjoyment; EXM: extrinsic motivation; PFM: professional motivation; SPHI: sharing of paid health information.
p < 0.05.
p < 0.01.
p < 0.001.
The numbers in brackets are the t values.
We first tested the relationship between various motives and sharing of paid health information by physicians. As shown in Stage 1, the effects of extrinsic motivation (β = 0.287, t = 4.858, p<0.01), enjoyment (β = 0.144, t = 2.429, p<0.05), and professional motivation (β = 0.109, t = 2.506, p<0.05) on physicians’ sharing of paid health information are significant, indicating H1, H2a, and H2b are all supported. These results suggest that extrinsic motivation, enjoyment, and professional motivation are all the motives behind physicians’ sharing of paid health information.
We further tested the moderating role of income ratio at Stage 2. As shown in Table 3, income ratio negatively moderates the effect of enjoyment (β = -0.172, t = 2.489, p<0.05), which is contrary to H3, while it positively moderates the effect of extrinsic motivation (β = 0.123, t = 2.210, p<0.05) and enjoyment (β = 0.198, t = 2.848, p<0.01) on sharing, supporting H4a and H4b. The R2 of the model at Stage 2 is significantly larger than the model at Stage 1 (0.412 vs 0.197), indicating a significant contingent role of income ratio.
Finally, we tested the moderating role of online reputation in Stage 3. The results indicate that online reputation exerts non-significant influence on the effect of extrinsic motivation (β = 0.287, t = 0.676, p>0.10), enjoyment (β = 0.010, t = 0.226, p>0.10), and professional motivation (β = -0.042, t = 1.057, p>0.10), indicating that H5, H6a, and H6b are not supported. The model at Stage 3 has a larger R2 than the model at Stage 1 (0.311 vs 0.197), which proves the important contingent role of online reputation.
4.4 Additional analyses
Because the moderating roles of online reputation were not supported, we conducted further analyses to better understand the effectiveness of the motives behind paid health information sharing. Following the procedures by Aiken et al. [67] and Cohen et al. [68], we piloted the marginal effects of extrinsic motivation, enjoyment, and professional motivation on physicians’ sharing of paid health information under different conditions of online reputation. Figures 3–5 show the results.

The marginal effect of extrinsic motivation under different levels of online reputation.

The marginal effect of enjoyment under different levels of online reputation.

The marginal effect of professional motivation under different levels of online reputation.
Figure 3 presents the marginal effect of extrinsic motivation on paid health information sharing. It shows that with the increase of online reputation, the effect of extrinsic motivation is weakened. Thus, H5 (online reputation weakens the effect of extrinsic motivation) is partly supported. The reason for the unsupported H5 in the main analysis can be that it is easier for physicians with a good online reputation to attract patients and gain monetary rewards, and thus they are more incentive-driven in sharing health information.
Figure 4 presents the marginal effect of enjoyment on physicians’ sharing of paid health information. It shows that the marginal effect of enjoyment increases with higher levels of online reputation, further partly supporting H6a. These results together show that with a good online reputation, physicians will be driven by their inherent interest.
Figure 5 demonstrates the marginal effect of professional motivation on physicians’ sharing of paid health information. It also shows that the marginal effect of professional motivation increases with higher levels of online reputation, which is consistent with H6b. This finding indicates that professional motivation becomes more effective in motivating physicians to share paid health information when they have a higher online reputation.
5. Discussion
The aim of this study was to investigate how different motivations, income ratio, and online reputation influence paid health information sharing by developing a theoretical model based on motivation theory. We then used an online survey to test the model. Three key findings contribute to the literature and provide implications for practitioners.
5.1. Key findings
First, extrinsic motivation, enjoyment, and professional motivation dominate as the major motives in prompting physicians to share paid health information. Consistent with the previous literature, we found that the extrinsic motivation induced by monetary incentives can positively motivate them to share health information. Our research context is the sharing of paid health information, providing an incentive-driven situation. Similar to the sharing of free health information, we also found physicians can also experience enjoyment and professional motivation from online health communities, which also motivate them to share paid health information.
Second, income ratio plays significant contingent roles in the motives for sharing paid health information. These research findings indicate that income ratio positively moderates the effect of enjoyment and extrinsic motivation, but negatively moderates the effect of professional motivation. This finding suggests that with a higher ratio of online to offline income, physicians will pay more attention to extrinsic motivation and enjoyment. This is because when have gained a higher level of online incentive from the online communities, they will be further motivated to seek more incentives and inherent enjoyment in sharing their knowledge. However, the moderating role of income ratio on the effect of professional motivation is negatively significant. This indicates physicians with a higher ratio of online income will pay more attention to the incentives and enjoyment, so they care less about using online communities to complete their professional tasks. Thus, we can claim that income ratio has different contingent roles on the effects of different motives on physicians’ sharing paid health information.
Third, our study findings suggest that the contingent role online reputation exists but less significant. In the additional analyses, we found the role of online reputation indicates that physicians with a higher online reputation will focus more on their enjoyment and professional motivation but less on extrinsic motivation. This is because physicians with an online reputation pay more attention to their intrinsic motives in participating in the online health community. However, in the main analyses, the moderating effects are all not significant. One possible explanation is that physicians pay more attention to offline reputation that relates to physicians’ rank, so they care not much about online reputation.
Finally, professional motivation can only be effective in motivating physicians to share paid health information in certain situations. In the analyses, we found professional motivation exerts a stronger effect when income ratio is at low levels and online reputation is high. This finding indicates that although extrinsic motivation and enjoyment play a dominant role in sharing paid health information, in certain situations, physicians can also be motivated by their professional motivation.
5.2. Theoretical implications
This research offers several theoretical contributions. First, this study distinguishes and explores a specific information sharing behaviour: paid health information sharing, which contributes to the knowledge-sharing literature. Although physicians’ online information-sharing behaviour has been widely explored, little current research has focused on paid sharing behaviour or analysed the underlying mechanism of the associated motives. This study identifies the motivations for physicians’ sharing of paid health information and further explored the determinants from a holistic perspective. To this end, this study expands the knowledge-sharing literature by identifying motivations for physicians’ sharing of paid health information and invites future research to focus more on this specific area.
Second, our research enriches the literature on health information sharing by identifying underlying mechanisms for paid health information sharing. Although several studies have explored physicians’ sharing of paid health information in online health communities, most of them have focused on the role of monetary incentives and neglected the characteristics of physicians as specific professionals. This study considers the professional motivation and enjoyment of physicians and further proposes income ratio and online reputation as contingent factors. In doing so, this study has developed a new mechanism for physician motivation: along with extrinsic motivation, professional motivation, and enjoyment can trigger paid information sharing in certain situations. Our findings not only increase current understanding of the motives for physicians’ online information-sharing behaviour but also highlight the effectiveness of different types of motivations in different situations.
Third, this study extends the motivation theory in the health care field by addressing professional motivation as a subdimension of intrinsic motivation. To better suit the physicians and explore their motivations, this study is one of the first to expand motivation theory by defining professional motivation as an obligation-based intrinsic motivation. Physicians, as a specific professional group, may have different mechanisms from those of general online users, but their characteristics have been largely ignored in the current literature, which generally explores their extrinsic and intrinsic motivation. This study is one of the first to identify professional motivation as a subdimension of intrinsic motivation to better understand physicians’ online behaviours. By doing so, this study reconciles the motivation theory by incorporating professional motivation into the theory to better suit physician groups.
Finally, the study also gains to the current understanding of the role of physicians’ income and reputation in information sharing. Previous studies on online health communities have shown that physicians’ income and reputation influence their behaviour in online health communities (9,36,34), but ignored the interplay of physicians’ online and offline properties. Therefore, by testing the online to offline income ratio and online reputation of physicians, we found that for physicians with different properties, their motivations for information sharing can systematically differ. These findings suggest that when exploring users’ online behaviour, their properties can be of significance in determining their behaviours.
5.3. Practical implications
This study also provides several implications for practitioners. First, platform managers can take steps to increase physicians’ extrinsic motivation, enjoyment, and professional motivation to promote their sharing of paid information. For example, to increase extrinsic motivation, managers can set reasonable incentive levels, use different incentives for different physician groups, or show the incentives physicians have obtained through them. To increase the enjoyment, platform managers can use some human–computer interaction features, such as using an online ranking system, make the interaction process more fun, and introduce attractions in the interface on the online communities. To promote professional motivation, managers can display labels like ‘Thank you for your help’ or ‘You have helped ** online patients’ after each answer to the patient’s questions. They can also design the online communities to make them like offline hospitals or clinics to evoke physicians’ obligation in the online context.
Second, managers can use different strategies to motivate different groups of physicians. Because, as we found, physicians’ income ratio will increase the effectiveness of extrinsic motivation and enjoyment and reduce the effect of professional motivation on sharing behaviour. Managers can use professional motivation to motivate physicians with a lower income ratio and use extrinsic motivation and enjoyment to motivate physicians with higher income ratio. For those with lower income ratio, managers can mainly use professional obligation to motivate physicians, such as emphasising the usefulness of their contribution to patients and their career development. For those with a higher income ratio, managers can pay attention to their inherent positive feelings and incentives obtained from the platform. We also found that online reputation does not moderate the effect of different motives. Thus, managers are suggested not to use online reputation to grouping physicians to motivate them.
Finally, physicians can better understand their decision-making process regarding the sharing of paid health information. Because physicians with different income ratios have different reliance on different motivations, physicians in different groups should pay attention to how their income ratios shape their sharing of paid information to make more informed decisions. For instance, physicians with a lower income ratio should know that their low income from online health communities may induce them to rely more on extrinsic motivation and enjoyment and less on professional motivation. This leverage may demotivate some of them contribute less and depart the communities.
5.4. Limitations and future directions
Although this study provides useful insights, it has its limitations. First, owing to privacy issues, we could not obtain physicians’ actual and accurate online and offline income. To better measure the extrinsic motivation and income ratio of physicians, we set income ranges in the questionnaire for physicians to respond to. Even though we set the measures based on the literature and field interviews, there may still be gaps between the constructs and measures, which may compromise our findings [69]. Second, we have only studied the contingent role of physicians’ income ratio and online reputation in the motives for their sharing of paid health information. There may also be other physicians’ properties, which future research could test further. Finally, online health communities in China provide a unique context for exploring physicians’ sharing behaviour, and we are not sure whether the findings can be extended to Western culture. This is another avenue for future studies.
6. Conclusion
Online health communities provide a platform for physicians to share free and paid health information with patients, which can benefit society. Nonetheless, the prior literature on knowledge sharing rarely provides insights into the decisions behind physicians’ sharing of paid health information. In this study, we drew on motivation theory to identify extrinsic motivation, enjoyment, and professional motivation to explain physicians’ sharing of paid health information under different levels of income ratio and online reputation. We found that extrinsic motivation and enjoyment are the major determinants of the sharing of paid information in different conditions, whereas professional motivation can only be effective in certain situations. Our research contributes to the literature on online health behaviour, physician behaviour, and motivation theory, and provides implications for practitioners.
Footnotes
Appendix A
Summary of Motivation Studies on Online Health Community.
| Motivations | Physician properties | Research context | Type ofsharing | References |
|---|---|---|---|---|
| Health information sharing behaviours in the United States | Voluntary | [70] | ||
| 128 top answerers an online health community (Yahoo! Answers) | Voluntary | [12] | ||
| Offline status | An online health community | Voluntary | [9] | |
| Physicians from Med. .net | Voluntary | [71] | ||
| Online health communities | Voluntary | [72] | ||
| 443 physicians in online health communities | Voluntary | [40] | ||
| Physicians in an online health community ( xinli001.com ) | Voluntary | [34] | ||
| Professional expertise and online expertise | Physicians’ in an online health community ( haodf.com ) | Voluntary | [5] | |
| Physicians in online health communities | Voluntary and paid | [73] | ||
| Past online reputation, doctor review rating, clinic title, hospital level, city level | Physician’s in an online health community ( haodf.com ) | Voluntary and paid | [35] | |
| Professional status | Physicians in an online health community ( haodf.com ) | Voluntary and paid | [36] | |
| Seniority | 28,848 physicians in an online health community | Paid | [7] | |
| Self-recognition and others’ recognition of physicians’ competence | 26,543 physicians in an online health community | Paid | [6] | |
| Professional status | Physicians from good doctor online | Paid | [36] | |
| Ranking | Physicians in an online health community ( xywy.com ) | Paid | [23] | |
| Tie with patients | Physicians in an online health community ( haodf.com ) | Paid | [74] | |
| Professional title | 26,543 physicians in an online health community | Paid | [37] |
Appendix B
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was partially funded by the National Natural Science Foundation of China (71901127 and 71902135) and Young Elite Scientists Sponsorship Program by Tianjin (TJSQNTJ-2020-12).
