Factors influencing ergonomists’ use of observation-based risk-assessment tools

2.1 Study design

This cross-sectional study has a mixed-method design. Data was collected using both a questionnaire and interviews. The questionnaire was used to investigate the use of OBRATs in a broader perspective and the interviews were used to provide a deeper understanding concerning the process of risk assessment assignments. The analysis and the interpretation of the mixed data was also inspired by Logan's and Graham's [11, 12] framework, the Ottawa Modell of Research Use (OMRU). The rationale to use this framework was that it can be used to study the use of research-based knowledge in practice and assist to identify factors of importance to understand the knowledge translation [11–13].

2.2 Questionnaire

A web-based questionnaire was used to quantify the use of research-based OBRATs. The questionnaire targeted Swedish OHS-employed ergonomists (RPTs), members of the Ergonomics Section of the Swedish Association of Physiotherapists. Information about the survey was sent out by the Ergonomics Section of the Swedish Association of Physiotherapists in a periodical e-newsletter addressed to all of their 598 members. Only members that opened the newsletter received information about the survey. Two reminders were sent. Of the 251 ergonomists who opened the newsletter, 107 (43%) completed the questionnaire. After applying the inclusion criteria (conduction of risk assessments >1 year), the study group consisted of 70 (28%) ergonomists. They provided service to various client companies in the private and the public sectors.

The questionnaire included questions about the ergonomists’ backgrounds (Table 1) and their use of OBRATs as well as attributes they considered important in them. Seventeen OBRATs were included based on the criteria that the tool should be available in Swedish or English and publicly available in Sweden. The OBRATs included originated primarily from Takala et al. [1] and were supplemented with five tools suggested by the research group and a reference group of ergonomists (Appendix 1). For each OBRAT, the ergonomists were asked if they had used the tool or not, or if they were unfamiliar with the tool. Depending on their answer, a set of subsequent dichotomous (yes/no) questions followed (Table 4). The ergonomists were asked how they had gained knowledge of these tools (e.g. through colleagues, education, professional sector-specific networks or via internet searches). They were also given the opportunity to provide free-text answers concerning the reasons for use and names of other OBRATs that they had used. Another 15 questions concerned important attributes of OBRATs in general (Fig. 1) using a five-point ordinal scale ranging from 1 (Not important at all) to 5 (Very important).

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Fig.1

Rating of important attributes of OBRATs in general. Results from the web-based survey. The respective proportions of respondents that gave a rating from 1 (Not important at all) to 5 (Very important) are indicated (see key).

2.3 Interviews

For the interviews, twelve OHS ergonomists (all RPTs) were recruited (Table 1) and gave their informed consent. Inclusion criteria were: ongoing employment as an OHS ergonomist and experience of risk assessments. Five of the ergonomists were recruited from a parallel research project [14, 15]. Contacts were taken with other OHS companies by the first author and an additional seven ergonomists were recruited to the study.

Three of the ergonomists were employed as ‘in-house ergonomists’ within a global industrial manufacturing company but worked at different production plants. Nine of the ergonomists were employed in external OHS companies situated in seven different regions in the southern and central parts of Sweden. The external OHS companies provided services to a wide variety of client companies in different work sectors, which meant that the number of clients differed across the external ergonomists. Six ergonomists described that they visited at least one client company regularly (>1/month) and can therefore be described as ‘partially in-house’. Unlike the in-house ergonomists, all external ergonomists had dual work roles, that is, they treated patients in addition to conducting work environment-related assignments.

Semi-structured interviews lasting 45 to 60 minutes were conducted. Nine of the interviews were conducted by the first author and three interviews were conducted by the second author. The interview guide used was developed through workshops within the research group and had been piloted on two ergonomists (RPTs), which resulted in slight modifications. The ergonomists were each asked to describe a risk-assessment assignment they had been involved in, how the assignment was initiated, what methods were used and how feedback and evaluations were given.

3.1 Initiation of assignments

Table 2 gives an overview of the ergonomist risk-assessment process with examples from the interviews analysis.

The ergonomists reported that assignments often were initiated reactively after occurrence of WMSDs (Table 2). Initiative was taken either by the client company, which contacted the ergonomist because one or more employees had reported WMSDs, or from the ergonomist, who contacted the client company when one or more employees in the client company underwent clinical treatment. Both ways to initiate the assignment resulted in the ergonomist visiting the client company, observing the employee/s at work and assessing physical exposures.

Another example of a reactive initiation of assignments was when an injunction had been issued by SWEA towards the employer due to lack of fulfilment of the employer’s legal health and safety obligations. It was described that the awareness among client-company managers with regards to responsibilities concerning OHSM was sometimes limited:

It emerged that proactive initiatives for ergonomic assignments were related to the maturity of the client companies’ OHSM. In some cases, it was clear that ergonomic assignments were important because they were integrated in the company's OHSM. A precondition seemed to be the relation between the OHS ergonomist and the client, for example the opportunity to be on site within client companies, to know the company. Mainly two types of proactive assignments were described. Periodical screenings at the client company, where the ergonomist visited different departments at the workplace and interviewed employees in a general screening designed to identify potential adverse physical exposures. Another proactive initiative was when the ergonomist was responsible for the periodical risk assessment of physical exposures within a client company.

Another, but less frequently mentioned example of a proactive initiation was when the client company contacted the ergonomist during the planning or design of new work tasks or workplaces:

A majority of the respondents in the questionnaire (70%), conducted risk assessments at least once a month (Table 3). The interviews revealed that the practice of identifying and assessing physical exposures were mainly based on the ergonomist’s own experience and expertise. A screening through direct observations without any specific method or tool, interviewing employees and taking still images or video footage of work tasks was often the practice to assess risk.

The survey explored the ergonomists’ knowledge about different OBRATs (Table 4). The results show the most commonly used OBRAT was the “Physical Ergonomics: Provisions of the Swedish Work Environment Authority” (SWEA-AFS) [18, 19], which was used by all ergonomists. Other commonly used OBRATs were, in descending order, “Key Item Method – Pulling, Pushing” (KIM I) [20] (51%), “Key Item Method – Lifting, Holding, Carrying” (KIM II) [20] (36%), “Quick Exposure Check” (QEC) [21] (27%) and “VIDAR” (an acronym for the Swedish expression Video och Datorbaserad ARbetsanalys (Video- and computer-based work analysis) [22] (27%) (Table 4). A majority of the ergonomists reported that important attributes that affected the use of SWEA-AFS [18, 19], KIM I [20], KIM II [20] and QEC [21] were that the tools were both easy to use and easy to communicate to the client company. About half of the ergonomists (40–53%) also reported that they were quick to use. However, the attributes of OBRATs with the highest proportion of ergonomists’ rating those attributes as very important were 1) easy to interpret for the client (77%), 2) have a clear client benefit (73%), and 3) be research-based (70%) (Fig. 1). Other important attributes were that the tool should: 4) be easy to use, 5) produce results that are easy to visualize, 6) be easy to adapt to different lines of businesses/work tasks, 7) provide a good basis for intervention proposals, and 8) produce results that are easy for the user to interpret. All but one attribute, ‘the tool being requested by the client’, were given a score of ≥4 by a majority of the ergonomists.

Education was the most frequently reported way of having gained knowledge of a tool (64%). Seventy-nine percent of the respondents in the questionnaire reported having additional education within ergonomics. The nature of the education reported varied from shorter courses (8 weeks) with specific focus at risk assessment and risk assessment methods, to university level master programs (1–2 years) in ergonomics. The number of OBRATs used was significantly higher among ergonomists with additional ergonomics education (Mann-WhitneyU-test, p = 0.004) (Table 3). Other ways of gaining knowledge of tools were through colleagues (20%), through internet searches (9%), and through sector networks (6%). There was no correlation between the ergonomists work experience and the number and the number of different OBRATs used. (Mann-Whitney U-test, p = 0.805)

The use of internationally well-known OBRATs was distributed as follow: NIOSH-Lifting Equation [23] (23%), RULA [24] (23%), REBA [25] (17%), the Strain Index [26] (11%), ACGIH-HAL [27] (4%), OWAS [28] (4%) and OCRA [29] (3%). Lack of knowledge/skill (including familiarity) was reported as the main reason for not using a tool. Other reasons were attributes related to the tool, such as being too complicated, too time-consuming or unnecessary. A further reason not to use OBRATs more extensively was expressed by one interviewee, who argued that the use of OBRATs led to less flexibility:

Subsequently, the results from the questionnaire regarding the use of OBRATs were confirmed by the interviewees. The ergonomists had knowledge of a number of different OBRATs but mainly used the SWEA-AFS [18, 19] (Table 4). However, the three in-house ergonomists worked, in contrast to the external ergonomists, solely with work environment-related assignments, and not as clinical physiotherapists treating patients. They used several risk-assessment tools, combining different OBRATs, direct measurements, interviews and footage/photos. The in-house ergonomists’ organization supported the use of a set of tools/OBRATs via a company policy.

Risk assessments were often summarised in a report and sent to the client company. In this process, OBRATs were sometimes used as references by the ergonomists when communicating physical exposures and risk factors for WMSDs to representatives within the client company.

Potential effects of risk reducing measures were most often not evaluated. The external ergonomists reported that a barrier to re-visiting and evaluating completed assignments was an economic factor, the inability to bill the client company for this service. Ergonomists working in-house or partially in-house expressed greater opportunities to follow-up and evaluate risk reducing measures. However, some of these assignments were described as more informal ‘follow-up checks’ and not systematic evaluations including before-and-after measurements.

Systematic evaluation was reported only by in-house ergonomists. They evaluated any possible changes in exposure after interventions by using the same tools that were used for the initial assessments.

In the OMRU framework, the innovation can be represented by various knowledge tools [12], which in this study is represented by the OBRATs. Table 5 presents ergonomists’ perception of what attributes in OBRATs motivate use. In accordance with Diego-Mas, Poveda-Bautista, and Garzon-Leal [4], the results indicate that OBRATs should facilitate decision making regarding risk reducing measures (here: provide an appropriate basis for intervention proposals) and be applicable to different types of jobs. However, issues related to training (e.g. ease of learning or requirements of training) seem to be of less importance. In contrast to the findings of Diego-Mas, Poveda-Bautista, and Garzon-Leal [4], an OBRAT’s being quick to use was identified as a factor of importance in the present study. This finding is concordant with Buckle and Li [31] and Rose et al. [32] and was proportionally high among those OBRATs that had proportionally high usage (Table 4). However, being quick to use seems, in agreement with Rose et al. [32], to be less important than being easy to use. The proportionally high rating of the tool’s being research-based might be unexpected, since the scientific basis of the three tools with the highest proportion of use (SWEA-AFS [18, 19] KIM I [20] and KIM II [20]) is somewhat unclear, and studies evaluating their ability to predict increased risk of WMSDs are lacking [33, 34]. However, the fact that these tools are promoted by a governmental body (i.e. SWEA) may give the impression that they are scientifically valid and reliable.

Potential adopters are those who may use the innovation [12]. In this study potential adopters are represented by the OHS ergonomists. The results show that education or training was an important factor that prompted the ergonomists to use different OBRATs, which is in agreement with findings from Arezes, Miguel, and Colim [35]. In the present study, there was a spread in education level among the respondents, ranging from shorter eight-week courses focused only on risk assessment to full university level master programs in ergonomics. The results showed that the number of different OBRATs used by ergonomists was significantly higher among those with an additional education in ergonomics (Table 3). However, the frequency of risk assessment assignments was similar among the groups (Table 3) which indicates the value of additional education. Even if the ergonomists knew of the existence of a number of different OBRATs, they stated that they lacked the skills to use many of them. This may contribute to less informative and less accurate risk assessments since different OBRATs focus on different dimensions of physical exposures, and a combination of several tools may be necessary for more comprehensive risk assessments [1]. For the eight tools with the lowest proportion of users, about half of the ergonomists stated that they were not familiar with these tools. This group included the OWAS [28], OCRA [29] and the Strain Index [26]. Interestingly, these tools were among the most commonly used OBRATs among Spanish-speaking ergonomics practitioners [4], and the Strain Index was used by about 40% of ergonomists in the U.S. [36].

It is possible that the dual work role which is common for Swedish OHS externally employed ergonomists, that is, acting as both a clinical physiotherapist treating patients and as an ergonomist conducting work environment-related assignments, may hinder the ergonomists’ ability to specialize and develop in-depth knowledge and skills concerning risk-assessment procedures and different OBRATs.

4.3 Practice environment; the context of the OHS ergonomists

In the OMRU framework, the practice environment is comprised by structural factors: e.g. policies, decision-making structure, rules, workload and current practice [12]. Identified factors related to the OHS ergonomists’ context include structural factors at several levels, all of which affect the use of OBRATs:

1) At a policy level, factors such as availability and promotion from regulatory bodies seemed to highly influence the use of different OBRATs. This is reflected in both results from the interviews and the questionarie. For example, the use of the NIOSH-LE [23] (23%), RULA [24] (23%), and the Strain Index [26] (11%) was lower in the present study compared to other surveys among certified ergonomists in the U.S. [36] and Canada [37] and among Spanish-speaking ergonomics practitioners [4]. These four OBRATs are contrary to SWEA-AFS [18, 19], KIM I [20] and KIM II [20] (Table 4) not promoted by a regulatory body in Sweden which likely affect their use.

The extensive use of SWEA-AFS [18, 19] confirms the results from earlier surveys in Sweden [38]. SWEA-AFS, KIM I and KIM II were all available from the SWEA website, and promotion from a regulatory body (in this case SWEA) is a likely contributor to high usage [31]. The interviews revealed that the SWEA-AFS [19], which is a provision issued by a regulatory body (SWEA) and is based on the Swedish Work Environment Act, could be used as an incentive for risk reducing measures, which indicates that support from regulatory bodies is a determinant for the use of OBRATs. However, both SWEA-AFS [18, 19] and VIDAR [22] (which is based on SWEA-AFS), are not systematic risk-assessment tools with quantifiable indexing; they can be considered screening tools instead.

2) At an organizational level, factors within both OHS companies and the client companies also seem to affect the use of OBRATs. Factors that can be assigned to the organizations of OHS companies are organizational support and routines for working with standardized tools. Structural factors at client companies involve the development of their internal OHSM. Interviewees described that the awareness among managers (at client companies) concerning responsibilities for OHSM varied considerably, and previous research support that small and medium-sized companies (especially) have difficulty fulfilling the requirements for their OHSM [39]. Schmidt et al. [40] describe that a well-developed OHSM at the client company is a key factor in using the OHS company effectively, promoting specialization and a more systematic approach [6], including the use of OBRATs.

Contextual factors that can be assigned both to the OHS companies and their clients are related to their relationship. A close relationship (e.g. in-house, partially in-house, opportunity to client company/sector specialization) and closeness to the client, with regular visits and long-term collaboration, seem to influence whether OHS services are used proactively or reactively. The interviews indicate a predominance of reactive assignments, which may explain the low use of OBRATs, as risk assessment can be regarded as predominantly a proactive action.

The relationship may be impacted by the contracts between OHS and clients. In Sweden, contracts between a company and an OHS provider are seldom preceded by a needs assessment and are often short term in character (1–3 years), which narrows the possibilities of establishing long-lasting relationships and results in external OHS companies’ often becoming passive recipients of assignments instead of working proactively together with the client company [41]. These preconditions may contribute to client companies’ mainly contacting the contracted OHS company after identification of WMSD problems (e.g. for rehabilitation), which also is described by Whysall, Haslam, and Haslam [7], and may hamper the use of the OHS company for preventive/proactive assignments. A contributing factor to this approach may be that client companies are unfamiliar with the ergonomist’s competence concerning proactive work [42], which is reported among engineers and design professionals [43]. However, there is not always a clear distinction between proactive and reactive, and the interview results indicate that it is possible for ergonomists to make use of a reactive assignment to initiate proactive work which involves risk assessment resulting in risk reducing measures targeting entire work groups.

4.4 Methodological considerations

Concerning the sample, the gender distribution of the questionnaire respondents (81% women) and the interviewees (75% women) is close to that of Swedish ergonomists in general (79% women), members of the Ergonomics Section within the Swedish Association of Physiotherapists, as was communicated in an e-mail to the authors.

The response rate of the questionnaire was 28%, and caution should be observed when generalizing these results to all Swedish OHS ergonomists. It is possible that the ergonomists that responded to the questionnaire have a special interest in risk assessments compared to those that did not. If so, the use of OBRATs may be even lower than reported in this study. However, 70% of the responders conducted risk assessment >1 month, we consider their answers regarding the use of OBRATs are representative among Swedish OHS ergonomists. Questions about seventeen OBRATs were included in the questionnaire. It seems to have covered the most commonly used OBRATs in this population, because only two additional OBRATs were reported, the Ergonomics Thermometer [44] and ‘SARA’ [45], both used by fewer than 3% of the ergonomists. Education or training was an important factor that stimulated the use of OBRATs. The questionnaire provided some opportunity for the respondents to elucidate what kind of additional education within ergonomics they had participated in, however more specific information concerning the content of the education is lacking. Hence, how to successfully design courses that facilitates the implementation of OBRATs needs to be further explored in future research.

Only twelve interviewees were included in this study. However, they represented both in-house and external OHS ergonomists with clients in several different sectors. The differences in their experience, (range from 4 to 25 years (mean 15 years) and the different organizational context covered different perspectives and experiences. Thus, we consider that the findings strengthen the ability to draw conclusions about the Swedish OHS ergonomists practice regarding risk assessment.