Chinese Herb Use by Patients at a San Francisco Chinatown Public Health Center

Abstract

Objectives:

Chinese herbal medicine (CHM) use has not been well characterized in persons living in the United States who receive care by Western-trained healthcare providers. The primary objective of this study was to characterize use of CHM taken in the last 12 months by patients seen at a Chinatown public health center.

Design:

Convenience sample survey.

Setting:

Data collection occurred over 3 months at a San Francisco Chinatown public health center.

Participants:

Adult patients visiting their primary care provider.

Interventions:

Completion of a voluntary 24-question survey on CHM use.

Outcome measures:

Prevalence, type, and indications for use.

Results:

Survey response rate was 29% (50/170). Seventy percent (35/50) of respondents had used CHM in the last 12 months and 94% (33/35) were also taking prescription medicines. The three most commonly used CHM were goji berry (37%), Dioscorea (31%), and ginseng (23%). The most common indications for herbs used in the last 12 months were general wellness (34%), cold/flu (25%), and headache (6%). Sixty-four percent of respondents had used Western medicine in combination with CHM within the last 12 months. Sixty-nine percent of respondents who used CHM did not tell their Western provider about this use. No patient had CHM use documented in the electronic medical record.

Conclusions:

Patients seen at a Chinatown public health center frequently used CHM products in conjunction with Western prescription medicines. Providers should routinely enquire about CHM use for health as a soup, tea, food, or pill and document this use in the medical record.

Introduction

The use of herbal medicine (HM) is a significant part of chronic disease state management among individuals of Chinese descent living in the United States.^1,2 In a large, nationally representative sample of 76,000 adults living in the United States, 17.7% had used a nonvitamin, nonmineral natural product in the past 12 months.³ The prevalence of HM use from national surveys of complementary and alternative medicine (CAM) among Asians living in the United States and, more specifically, Chinese living in the United States is significantly higher (30% and 32%, respectively) but has been poorly characterized for type and indication.^2,4 Surveys conducted in California have found a higher estimate of HM use. For example, the general use of biologically based therapies (herbs, supplements, and vitamins) was 83% among Chinese living in California who participated in the California Health Interview Survey of Complementary and Alternative Medicine.⁵ The use of traditional Chinese herbal products has been estimated at 93% among foreign-born Chinese immigrants living in California.⁶ Despite a high prevalence of use, few details are provided in the literature about the specific HM products being used, the frequency of use, indication for use, and formulation among Chinese adults living in the United States.¹

Perceptions of HM use as compared to Western medicines have been described in the literature. One study of Chinese adults living in Hong Kong found that Western medicines are perceived to be more powerful than HM but are associated with more side effects.⁷ HMs, however, are thought to cure the root cause of the disease but take longer to work and require additional preparation time (e.g., boiling the herb).⁷

Despite the high usage rate of HM, many Western-trained healthcare providers have a limited understanding of its use and potential for interactions with Western medicines.⁶ Awareness of HM use is important for those caring for patients of Chinese descent, who are more likely to use these products than other adults living in the United States.

The purpose of this study was to identify the types of Chinese HM (CHM) taken in the last 12 months by patients who sought care at a San Francisco Chinatown public health center in California. Located in Chinatown, the clinic provides chronic care for 5000 patients who are mainly monolingual Chinese-speaking. Patient visits to this clinic are commonly associated with chronic disease state management and preventive health measures (e.g., vaccination, health screening). This study aimed to describe the demographic characteristics of those who used CHM and to characterize the prevalence, indication, and frequency of CHM use, along with the formulation and method of procurement. A secondary goal was to screen for potential interactions between the most commonly used CHM and Western medicines. Patients were also queried regarding their perceptions of Western-trained doctors versus Traditional Chinese Medicine (TCM) doctors.

Materials and Methods

A 25-question survey was created to assess CHM use by patients at a San Francisco Chinatown public health center. Survey questions were written in both English and Chinese. The Chinese-language survey was prepared by one of the researchers, who is a Chinese-speaking pharmacist (O.H.), and was reviewed by a Chinese/English-language certified hospital translator. A study investigator (O.H.) asked participants to complete the survey but did not administer the survey since it was already written in Chinese. Survey collection occurred over 3 months and was self-administered or facilitated, if participants had questions, by the pharmacist (O.H.). In the former case, surveys were placed in the clinic waiting room; patients completed the informed consent, filled out the survey, and placed the completed survey in a locked box. The survey was voluntary, and patients could decline to participate at any time. The survey was approved for distribution by the Committee on Human Research at the University of California, San Francisco.

Survey questions that characterized the patient population included questions about sex, age, country of birth, time living in the United States, primary language spoken at home, and level of education. Questions specific to CHM use asked patients to list the names of the three most common CHM products that they currently use or had used in the last 12 months for their health. For each CHM used, patients were asked to describe reason for use, frequency of use (daily, weekly, monthly, a few times a year or less), formulation (pill, tea, soup, or other), and perceived effectiveness (very helpful, somewhat helpful, not at all helpful, or unsure if helpful). Additional survey questions asked about each patient's CHM purchase source, monthly CHM expenditures, whether they informed their doctor about CHM use, and their perception of the effectiveness of CHM as compared to Western medicine.

Regarding Western medicine use, patients were asked whether they used Western medicines and to estimate how much they spend, on average, per month on Western medicines ($10 or less, $11–$24, $25–$49, $50–$100, or >$100). Finally, the survey asked about the resources patients primarily use to obtain information on CHM and Western medicines. Patients were also asked to indicate their type of primary healthcare provider (TCM doctor, Western doctor, both, or no regular primary provider) and whether they had a provider preference when not feeling well.

Electronic medical records of the survey participants were reviewed for information on their medical history and use of Western medicines. The top four commonly used CHM products were screened for potential drug and disease state interactions by using each patient's health record and the database Natural Medicines.⁸ The exact CHM term provided by the respondent was used to search for interactions. Interactions between CHM products and caffeine or CHM products and alcohol were excluded. Participants had to be a patient of a San Francisco Chinatown public health center and at least 18 years of age. As an incentive, patients who participated in the survey were entered into a raffle for one of four $25 gift cards to Safeway Inc. grocery store.

Results

Of 170 surveys distributed, 50 (29%) were returned completed. Survey respondents were mainly female, were aged 40–79 years, were born in China, had been living in the United States for 11 years or more, had attended school for 10 or more years, and spoke Cantonese at home (Table 1).

Table 1.

Patient Demographic Characteristics (n = 50)

Characteristic	Respondents, n (%)
Sex
Male	12 (24)
Female	38 (76)
Age
18–39 yr	3 (6)
40–59 yr	21 (44)
60–79 yr	24 (48)
80–99 yr	2 (4)
Country of origin
China	41 (82)
Hong Kong	2 (4)
Philippines	2 (4)
Vietnam	2 (4)
Other	3 (6)
Years in United States
0–1	4 (8)
2–5	11 (22)
6–10	5 (10)
≥11	30 (60)
Primary language spoken at home
Cantonese	33 (66)
Mandarin	5 (10)
Cantonese + Mandarin	5 (10)
Other	7 (14)
Years attended school
≤1 yr	5 (10)
2–5 yr	8 (16)
6–10 yr	15 (30)
≥11 yr	22 (44)

Thirty-five respondents (70%) had used CHM at least once in the last 12 months for their health, and 42 respondents (84%) had used CHM for their health at one time in their life. There were 44 CHM that respondents listed when asked for the top 3 products used in the last 12 months (Table 2). Respondents did not list the plant genus and species by using binomial nomenclature. The most common products being used were Lycium fruit (13/35 [37%]; 6 respondents listed Goji berry and 7 listed wolfberry), Dioscorea (11/35 [31%]; 5 respondents listed Dioscorea, 3 listed huai shan, 2 listed wai sun, and 1 listed shan yao), ginseng (8/35 [23%]; 2 respondents listed Chinese varietal ginseng, 1 listed American ginseng, 1 listed American and Korean ginseng, and 4 listed ginseng of unspecified origin), dong quai (6/35 [17%]), and ling zhi (4/35 [11%]). A majority of those using Dioscorea also used Goji berry (10/11 [91%]). There were 16 unique uses and 108 responses listed for CHM indications in the last 12 months. The most common uses were general wellness (37/108 [34%]), cold/flu (27/108 [25%]), and headache (7/108 [6%]) (Table 2).

Table 2.

Chinese Herbal Medicine Products Used and Associated Indications (n = 35 Patients; 44 Unique Herbs)

Herb ^a	Reported frequency of herb use (n)	Reported indications ^b
Lycium fruit (goji berry or wolfberry)	13	General health (7); clear vision (3); cold/flu (2); arthritis (2); release heat (1); neck pain (1); headache (1); sleeping (1)
Dioscorea (huai shan, shan yao, wai shan)	11	General health (7); cold/flu (2); arthritis (2); release heat (1); body weakness (1); neck pain (1); headache (1); sleep (1)
Ginseng (American, Chinese, Korean or unspecified species)	8	General health (6); cold/flu (4); joint pain (1); menstrual bleeding (1)
Dong quai	6	General health (5); menstrual bleeding (1)
Ling zhi	4	Cancer (1); general health (1); cold/flu (1); arthritis (1); releasing poison (1); sleeping (1)
Ban lan gen	3	Cold/flu (3)
Buk kei	3	General health (2); neck pain (1); headache (1)
Chuan Bei	3	Cough (2); cold/flu (1)
Xia ku cao	3	Release heat (2); cold/flu (1)
Dong sum	2	General health (2); arthritis (1)
He shou wu	2	Headache (1); menstrual bleeding (1)
Other^c	33	Cold/flu (13); general health (7); stomachache (4); headache (3); menstrual bleeding (3); joint pain (3); back pain (2); sleeping (1)

Respondents did not list Chinese herbal medicine products using Latin binomials.

Each herb may have been used for more than one indication.

Various individual herbs mentioned once.

Respondents who had used CHM in the last 12 months used 2 (31%) or 3 or 4 (29%) different products, while a smaller subset used 5–10 (23%) or more than 10 (14%) different products (Table 3). CHM products were typically prepared as a soup (58% of 95 responses) or a tea formulation (23%); were used a few times a year or less (42%), monthly (26%), or weekly (23%); were perceived as being very effective (55%) or somewhat effective (32%); and were purchased from a Chinese herbalist in the United States (57% of 35 respondents) or a grocery store in the United States (23%) (Table 3). Respondents commonly spent $10 or less per month (37%) or $11–$25 per month (31%) on CHM products.

Table 3.

Characteristics of Chinese Herbal Medicine

Characteristic	Respondents, n (%)
CHM formulation (n = 95 responses)
Soup	55 (58)
Tea	23 (24)
Pill	12 (13)
Other	5 (5)
Frequency of use (n = 92 responses)
Few times a year or less	39 (42)
Monthly	24 (26)
Weekly	21 (23)
Other	8 (9)
Perceived effectiveness (n = 92 responses)
Very	51 (55)
Somewhat	29 (32)
Not sure	8 (9)
Other	4 (4)
Purchasing source (n = 35 respondents)
Chinese herbalist in United States	20 (57)
Grocery store in United States	8 (23)
Import from Asia	3 (9)
Other	4 (11)
Estimated monthly expenditures (n = 35 respondents)
≤$10	13 (37)
$11–$25	11 (31)
$26–$50	7 (20)
$51–$100	3 (9)
>$100	0
No response	1 (35)

The use of Western medicine was prevalent, with 88% of all survey respondents reporting use of at least one Western medicine. This accounted for 199 Western medicines in total, based on the medicines documented in the electronic medical record, and an average of 4 Western medicines per patient. The most common indications for Western medicines were hypertension (26%), cholesterol (26%), diabetes (15%), osteoporosis (11%), and pain (7%). No respondents were receiving warfarin (patients receiving anticoagulation are not usually managed at this clinic). On average, each patient had 3.8 chronic disease states. Respondents commonly spent $10 dollars or less per month (57%) or $11–$25 per month (25%) on Western medicines.

Concomitant use of a Western medicine and a CHM product in the last 12 months was also prevalent, with 32 (64%) of respondents indicating combined use. Sixty-nine percent of those using a CHM product in the last 12 months did not tell their Western provider. Additionally, for all respondents who reported using CHM in the last 12 months, CHM use was not documented in the medicine list of the electronic health record. The potential for CHM and Western drug interactions was discovered in respondents taking ginseng and goji berry. Of the 8 respondents who reported taking ginseng, 5 were taking diabetic medicines, 4 were taking daily aspirin, and 1 was taking an antiestrogen for breast cancer. Three respondents taking goji berry were also taking diabetic medications. No potential drug or disease interactions were observed for Dioscorea or dong quai. Interactions for less commonly used herbs were not assessed.

Respondents preferentially relied on physicians (66%) and pharmacists (25%) for health information on Western medicine. In comparison, respondents relied on friends and family (51%) and Chinese herbalists (15%) for health information on CHM.

Although all survey respondents saw a Western-trained provider at the clinic, 15 (30%) also sought care from a TCM doctor. Respondents who already had a TCM doctor had a desire to see both types of doctors (11/15 [73%]) when ill. For respondents who saw only a Western-trained provider, a majority (21/35 [60%]) preferred to see their Western provider when ill; 37% would want to see both types of doctors when ill, if they could.

Discussion

The study population was mainly female, was aged 40–79, was born in China, had lived in the United States for 11 years or more; and spoke Cantonese at home. Because the clinic population is 65% female, the 76% proportion of our study sample being female is representative of the greater clinic population. The other patient demographic characteristics are consistent with the clinic's being located in Chinatown and serving Chinese-speaking patients.

CHM use was common in the study population, averaging 70% use in the last 12 months and 84% lifetime use. This is a higher prevalence as compared with national trends of general HM use in Asians and Chinese living in the United States, where average use is 30% and 32%, respectively.^2,4 Existing surveys have targeted use of complementary and alternative medicine where HM use is a subcategory, while others have used varying definitions of herb use, including the terms dietary supplement, herbal remedy, botanical supplement, biologically based supplement, and medications derived from plants and herbs.^2,4 This study focused predominantly on Chinese adults receiving care at a Chinese public health center in San Francisco and asked more specifically about CHM use, which could account for these observed differences. This study, however, did not give a strict definition of the term CHM, allowing respondents to self-report any Chinese herbs that they used medicinally for their health. Other studies that have surveyed Chinese living in the United States about CHM use have shown similarly high prevalence rates ranging from 82% to 93%.^1,6 This study was translated in Chinese and a Chinese-speaking pharmacist was available to answer questions for patients taking the survey, which may have also increased patient understanding and desire to take the survey.

Because this study was conducted in a Chinatown public health center, the population reflected patients with chronic disease states routinely managed by a Western doctor. The types of chronic disease states that respondents were treating with Western medicines were consistent with the most common diagnoses for visits to a Chinatown public health center (e.g., hypertension, hyperlipidemia, type 2 diabetes), where a majority (88%) were using at least one Western medicine. Interestingly, patients who used CHM products did not use them commonly for chronic disease state management but rather for general wellness (34%), acute relief of cold and flu symptoms (25%), and headache (6%). The only chronic health condition commonly treated with CHM products was chronic pain associated with neck, back, and joint pain and arthritis (43%). The idea of taking CHM products for wellness is in keeping with how the general population of Americans use dietary supplements to “improve” or “maintain” overall health (33%).⁹

Goji berry (Lycium fruit), Dioscorea, ginseng, dong quai, and ling zhi were the most commonly reported CHM products used. Products were primarily purchased from a Chinese herbalist and prepared as a soup or tea. Another study of CHM use among residents of San Francisco and Oakland Chinatowns found these herbs to be highly prevalent and similarly prepared.¹ Because of the cultural perception among Chinese patients that healing is achieved through food and that herbal products are food, it is not surprising that these types of formulations were common.¹

It is important to note that there were a limited number of uses for the 44 products cited, 16 in total. Healthcare providers caring for Chinese patients living in the United States can benefit by knowing which CHM products are frequently used for health, inquiring about current use as part of a complete medicine history and documenting use in the medical record. This would also help address the lack of CHM disclosure by patients. Among all patients who participated in this survey, CHM use was not documented in any part of the electronic health record or within each patient's medicine list. This lack of documentation may be related to how CHMs are prepared: A soup or tea may be viewed as food rather than a medicine or dietary supplement. Without this information, it becomes difficult to adequately screen for possible herb–drug or herb–disease interactions. Healthcare providers should use their clinical judgment in documenting use of CHM, whether prepared as a soup or tea or taken in a supplement form, if it is being used medicinally for health.

Sixty-four percent of respondents reported concomitant use of a Western medicine with a CHM product in the last 12 months. The degree to which a CHM–drug or CHM–disease interaction is likely to occur is based on the potency and purity of the preparation. Prepackaged formulations that are made using good manufacturing practices are likely to have greater consistency in potency as compared with self-prepared raw herbs. Drug information databases, such as Natural Medicine, most commonly list interactions by herb that are commonly based on prepackaged formulations studied in clinical trials or products documented in individualized case reports.⁸ When this study screened for interactions, an interaction was viewed as possible if a patient was taking a medication or had a disease state that was listed in the “Herb–Drug” or “Herb–Disease” interaction section of the Natural Medicine database.⁸

The potential for an herb-drug interaction was noted in six of the eight respondents taking ginseng and in three of the respondents taking goji berry. Specifically, six respondents used ginseng (American species, n = 1; American and Korean species together, n = 1; Chinese species, n = 1; unspecified species, n = 3) along with aspirin (n = 4), medications for type 2 diabetes (n = 5), or anastrazole (n = 1). Ginseng has been observed to have antiplatelet and hypoglycemic properties, which could potentiate the risk of bleeding and hypoglycemia, respectively.^8,10
–12 Ginseng may have estrogenic properties, which could be detrimental in a patient taking anastrazole for breast cancer.¹³ Three respondents were taking goji berry along with medications for type 2 diabetes. Goji berry may have hypoglycemic properties, which could potentiate the risk for hypoglycemia.^8,14 Ginseng and goji berry may have immune-enhancing effects and should not be taken by individuals receiving immune suppressant medications.^8,15,16 No respondents in this study were taking immunosuppressant medicines while taking these herbs.

Despite these instances of combined medication and CHM use, no instances of hypoglycemia or antiplatelet effects (bleeding/bruising) were documented in the respondents' medical records. None of the respondents in this study who were using Dioscroea or dong quai were taking warfarin or hormonal supplements, which negated the potential for interactions with these products.⁸

Most participants reported using CHM a few times a year or less, and fewer reported using CHM monthly or weekly. This is consistent with the reported conditions being treated including cold/flu and headache, which cause discomfort episodically, and is inconsistent with general wellness because that would require regular use. Another important finding is that respondents used CHM to treat cold/flu or pain (arthritic, joint, neck, or back pain), which are common disorders treated in Western medicine with over-the-counter medicines, such as acetaminophen or ibuprofen. Respondents tended to use CHM for self-limiting illnesses and used prescription medicines for chronic health conditions, such as diabetes or high cholesterol. This pattern of use reflects the attitudes of many Chinese immigrants, who believe that Western medicines are “stronger” and used in more serious disease states.⁷ The idea of an integrated approach to self-care is also reflected in the high prevalence of respondents, regardless of CHM use, who used or desired to see both a TCM doctor and a Western doctor when feeling ill.

Respondents reported spending $10 monthly for CHM as compared to $11–$25 monthly for Western medicines. This is consistent with the belief that CHM is natural, safe, and less expensive than Western medicines.¹⁸ CHM may account for more out-of-pocket spending than Western medicines, however, because it is less likely to be covered by health plans.

Most respondents who used CHM did not disclose their use to Western providers. Even if respondents did disclose their CHM use, there was no evidence of documentation in the electronic medical record. For providers to ask about herb use comprehensively, it would be helpful to ask about herbs used medicinally for health taken as foods (e.g., tea, soup) as well as those taken as dietary supplements (e.g., tablets, tinctures) because herbs prepared as food were most common. This study showed that respondents more commonly relied on friends and family for information about CHM. This increases the potential for misinformation regarding appropriate indications for use, side effects, and duration of use. An advantage, however, is that the cultural use of CHM is passed down from generation to generation, leading to a sharing of information on how to prepare medicinal herbs for health.

The limitations of this study include a relatively small sample size, which limits external generalizability; however, a 29% survey response rate represents a reasonable sampling of the clinic population in this health center. Previous studies assessing CHM use have identified the difficulty of obtaining information about herb use given the diversity of terms used to define herbs, variability in health literacy, and the different ways in which herbs are prepared (e.g., as a soup/tea/pill).¹ This study was prepared in the target language (Chinese) by a native speaker and reviewed by a Chinese/English-language–certified hospital translator so as to maintain consistency and minimize confusion regarding CHM terms and method of herb preparation. Because this study was a cross-sectional convenience sample survey, recall bias may have affected the degree of CHM use reported in the past 12 months. However, it is unlikely that recall bias affected the types of CHM reported because previous surveys in the San Francisco Bay area identified the same CHM products being used. Because of the survey method used, respondents did not list herb names by using the Latin binomial nomenclature with genus and species. As such, certain CHMs (e.g., wolfberry and goji berry) were grouped together Under the name goji berry; this grouping is consistent with the fact that both of these names are listed in the Natural Medicine database under the monograph for Goji. The lack of genus and species information limits the ability to conclusively relate the potential for drug and disease interactions to an herb, if one were to occur. Interactions are also specific to the formulation being used, which limits broad-based generalizability using the herb name alone.

Conclusion

A majority of survey participants had used both Western medicines and CHM together in the preceding 12 months. CHM use was not documented in the medical record. To screen for potential interactions between Western medicines and CHM, providers caring for patients of Chinese descent should routinely inquire about CHM use (as a soup, tea, food, or pill) if the herbs are being used medicinally for a health-related condition and document use in the medical record. Providers can educate themselves on frequently used CHM in order to serve as an informed resource to patients.

Footnotes

Acknowledgments

The authors thank Dr. Albert Yu for his support of the study and review of the study protocol.

Author Disclosure Statement

No competing financial interests exist.

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