Changes in attitudes toward and patterns in traditional Korean medicine among the general population in South Korea: a comparison between 2008 and 2011

Background Traditional Korean medicine (TKM) is acknowledged to be prevalent among the Korean public, but few follow-up studies are available to confirm this commonly held belief. Whereas most survey studies have focused on the demographic factors influencing the usage of TKM, only a few studies have conducted a pattern or trend analysis over time. The purpose of this paper is to observe and document recent trends in the usage of TKM in South Korea and to compare overall patterns of TKM use over a period of several years. Methods A cross-sectional survey was conducted in 2011 to assess TKM usage patterns and public perceptions regarding TKM. An online questionnaire was administered to consenting respondents that focused upon individual preferences between TKM and current Western medicine, respondents’ reasons for using TKM, the frequency of respondents’ visits to TKM clinics, the reasons respondents visited TKM clinics, and respondents’ perceived satisfaction. Results The results revealed that 66.6% of the respondents showed a positive attitude toward TKM. In addition, 69.3% of the respondents had visited TKM clinics one to four times during the previous year. Patients used TKM with the intentions of receiving acupuncture (95.3%), moxibustion (40.1%), and cupping (36.0%) treatments or to take herbal medicines (35.7%). Most respondents who had visited TKM clinics were largely satisfied with the clinics’ effectiveness (56.1%). The factors most commonly associated with TKM usage included sex (female), age (50s), and education (college or higher), but the within-factor differences were not significant. Compared with a previous survey of other groups, TKM usage was found to have increased from 45.8% in 2008 to 69.3% in 2011. With the exception of acupuncture and physical therapy, most usage doubled or more than doubled. Conclusions The attitudes toward and usage of TKM in South Korea have improved between 2008 and 2011. This result will be used to explain outcomes of certain social phenomena and to argue for national support in the promotion of TKM. Electronic supplementary material The online version of this article (doi:10.1186/1472-6882-14-436) contains supplementary material, which is available to authorized users.


Background
Complementary and alternative medicine (CAM) is widely used by both healthy people and patients with various medical problems in many countries. Nearly half of the population in many industrialized countries, including the U.S., Australia, France, Canada, and Japan, commonly use CAM therapies, and CAM usage is also increasing in many developing countries, including China, Chile, Colombia, and Taiwan [1][2][3]. Thus, studies aiming to identify the factors influencing the use of CAM have been conducted in many countries. The findings from these studies correlate CAM usage with age, race, gender, education, ethnicity, income, geographic residence, disease state/health, employment, spiritual/religious philosophies, the availability of health insurance, and sexual orientation [4,5].
CAM consists of a large and heterogeneous array of techniques and includes both therapeutic and diagnostic approaches [6]. Therefore, it is difficult to clarify or consolidate its definition, although many efforts have been made to define CAM in terms of concepts and models. Depending on an author's perspective, the number of CAM therapies can range from four to 16 [7]. The National Center for Complementary and Alternative Medicine (NCCAM) defines CAM as a group of diverse medical and health care systems, practices, and products that are not currently considered conventional medicine [4,8,9]. As so defined, CAM has a broad range of implications.
TKM, as a subset of CAM, is a popular source of health care in South Korea that has been passed down from generation to generation for centuries [10] as an integral part of common cultural practices and beliefs. Whereas Western medicine is built on reproducible experiments and statistical analyses [11], TKM is based on ancestral experience. Currently, Koreans are showing considerable interest in TKM, which is reflected in a substantial financial market for TKM. Since the time when TKM was first covered by national health insurance, its usage rate has increased significantly [12]. The majority of TKM users report that they have received various services to treat diseases or to use as secondary treatments while receiving conventional care. Positive perceptions of the effectiveness of TKM are a major determining factor in its use.
The aim of this study was to improve our understanding of the general perceptions of TKM by illustrating users' characteristics, TKM usage frequency, and users' preferences relating to these therapies by examining data from 2011. In addition, this study sought to gain insight into developing trends in TKM consumption by comparing the data employed in this study with earlier surveys conducted by other groups.

Questionnaire
This study was approved by the ethical review committee of the Korea Institute of Oriental Medicine (KIOM), located in South Korea. Participants who agreed to complete the survey first provided their informed consent. The survey instrument was designed to include questions regarding TKM utilization, self-perception, types of CAM use, reasons for choosing TKM, and the frequency with which the respondent visited TKM clinics. To assess TKM usage (as opposed to CAM usage) and to ensure comparability with the 2008 survey conducted by Shin et al. [12] (referred to herein as the "2008 survey"), we adjusted the questionnaire to contain the following TKM modalities: acupuncture, moxibustion, cupping, physical therapy, herbal medicine, Chuna (including chiropracty and any type of manual therapy primarily designed to address or relieve back pain), and other modalities based on the 2008 survey [12]. Non-TKM therapies that are still considered CAM were excluded from this study, including treatments based on vitamins, honey, compound nutrient pills, meditation, and breathing exercises. To ensure the accuracy of the data that were collected, certain questions were designed to allow multiple answers (Additional file 1).

Participants
The survey was administered via Macromill Embrain (http://www.embrain.com), one of the largest survey companies in South Korea, which was engaging 1,010,000 panelists at the time of our survey. We designed the survey with a target sample of 1,000 of these panelists by applying proportional quota sampling to those asked to participate in the study. We conducted our web-based survey between September 17 and December 8, 2011. Eligibility was limited to those who were 20 years of age or older. Among the respondents, 499 (49.9%) were male, and 501 (50.1%) were female. The participants were distributed across the country in five large metropolitan cities in South Korea: Seoul, Daejeon, Daegu, Pusan, and Gwangju.

Comparison of the 2008 survey with our 2011 survey
To minimize heterogeneity between the 2008 survey and our survey, we had numerous meetings with Dr. HK Shin, the main author of the 2008 survey, in which we asked for advice in designing the survey and in analyzing the data. Dr. Shin has been working for our institute, KIOM, and is interested in our survey because it was the first cross-sectional survey conducted since 2008. The questionnaire that we used contained nearly the same checklists as his survey, and we followed his protocols as much as possible. In addition, the socio-demographic ratios among the participants, the age distributions of the participants, and the dates of the year in our survey were similar to those same features in the 2008 survey [12].
Because our survey instruments were mostly determined by the 2008 survey, we did not evaluate validity and reliability. However, we consulted with some experts about whether the questions were clear, understandable, and presented in a logical order prior to conducting the survey.

Statistical analysis
All data collected in the survey were analyzed using SAS 9.3 (SAS Institute Inc.). The data were assessed using Pearson's chi-square test to compare categorical variables between TKM use and the socio-demographic characteristics of the respondents. Student's t-test was applied to assess the continuous variables.

Reliability of TKM compared with western medicine
A total of 1,000 participants were included in this study. The socio-demographic characteristics of the survey samples are shown in Table 1. The participants' ages ranged from 20 to 69. Figure 1 demonstrates that the majority of the participants trusted both TKM and Western medicine. There was no significant difference with respect to gender. However, people aged 50 to 59 reported higher rates of TKM reliability (75.7%) compared with older and younger people. Notably, there was a slight positive trend in the tendency to trust TKM as the participants' ages increased, at the following rates: 61.8% of those in their 20s; 63.3% of those in their 30s; 66.7% of those in their 40s; and 75.5% of those in their 50s. Similarly, there was a positive trend The percentage of trust was the sum of "strong trust" and "some trust". † The percentage of distrust was the sum of "no trust" and "little trust".
in the respondents' favorable attitudes toward Western medicine as the participants' age increased, at the following rates: 69.6% of those in their 20s; 72.2% of those in their 30s; 74.0% of those in their 40s; and 77.7% of those in their 50s. The reliability of TKM was perceived to be highest among those in their 50s who were college graduates and residents of Seoul. The participants who expressed trust in TKM also tended to place strong trust in Western medicine (85.6%).

Reasons for trusting TKM therapies
The survey asked about the participants' reasons for trusting TKM therapies. Because several reasons were predicted, the question was structured to allow for multiple answers. The results indicated that participants' primary reason for trusting TKM was because it has been proven useful by its utilization for hundreds of years (58.0%) or because it had been proven safe because of a low rate of side effects (52.7%). The other reasons were effectiveness (35.2%), comfort (24.6%), and strong reputation (15.7%). A small percentage of respondents felt that TKM was reliable because doctors had explained it well to them (7.9%) or because information on TKM has become more generally available to the public (4.8%) (data not shown).

Frequency and type of TKM therapy usage
Of the respondents, 69.3% had visited TKM clinics at least once during the past 12 months. More than half (53.4%) of the general population visited TKM clinics anywhere from one to four times. Moreover, 6.6% of the general population had used TKM therapies more than 10 times in one year. Visits to TKM clinics were not correlated with any demographic factors. Only small exceptions appeared with age. The percentages of respondents who had visited TKM clinics more than 10 times were 5.8% for those in their 20s, 4.6% for those in their 30s, and 5.2% for those in their 40s, whereas those percentages were increased approximately two-fold for patients in their 60s (10.9%) ( Table 2). Of the TKM clinic visitors, the majority received therapeutic treatments such as acupuncture, cupping, and moxibustion (67.7%), whereas 18.6% took traditional herbal medicines. Notably, even the respondents who did not particularly trust TKM also showed a tendency to take traditional herbal medicines and/or to receive health consultations at TKM clinics ( Table 3). Table 4 summarizes individual preferences regarding the types of TKM therapies. Because many CAM users report that they prefer using combined therapies over singular therapies [8], this part of the questionnaire was designed for multiple answers. The most popular therapy was acupuncture (95.3%), followed by moxibustion (40.1%), cupping (36.0%), herbal medicine (35.8%), Chuna (10.9%), and physical therapy (0.4%). Regardless of gender, age, educational level, or TKM reliability, most TKM users had received acupuncture treatment.

Usage of TKM therapies
The moxibustion users were predominantly in their 40s and 60s. Taking traditional Korean herbal medicine was more common among seniors (24.7% of those in their 20s compared with 43.1% of those in their 60s).

Comparison of previous TKM surveys in South Korea
Previous publications were used to compare the changes in TKM usage in South Korea over time. Three major TKM public surveys were conducted in 1999 [13], 2006 [14], and 2008 [12]. However, there was an enormous difference in the prevalence of TKM users between 1999 and 2006, when the proportion of the population using TKM jumped from 29% to 74.8%, as shown in Table 5. This disparity, however, was shown to have resulted from different definitions of TKM and the different modalities applied in each survey. These surveys also covered and included several nontraditional Korean therapies as CAM rather than TKM, including Ayurveda, music and art therapy, and dietary supplements such as vitamins and minerals. Because of the disparities in these reports, it is therefore impossible to clearly identify trends in TKM usage by comparing these  Figure 2).

Discussion
In the present study, we aimed to investigate the frequency, types, and factors associated with TKM usage among South Koreans. Although the entire population is covered by medical insurance and many people were familiar with various modalities as the major form of health care [15], others were opposed to TKM because of the lack of scientific evidence regarding its practices, adverse effects resulting from treatment, or because of the financial burden [5,12]. Nevertheless, we found that two-thirds of our sample population used some type of TKM therapies in 2011. In 1999, the first national survey on TKM use among the general population was conducted. The results indicated that 29% of the population had used TKM within the preceding 12-month period. The out-of-pocket expenditures for CAM had grown to 40.8% of those for Western medical services [13,16]. The next survey was conducted in 2006. The results indicated that 75% of adults reported some type of TKM therapy during the past year, for which the median annual out of-pocket expenditures were approximately US $203.6 per person [14]. Ock et al. suggested that the sudden increase in TKM users might be explained by the different definitions of TKM used in the two surveys. Similar to CAM [17], TKM encompasses a broad spectrum of practices and modalities. It was assumed that different age distributions were another reason for this difference. The authors had excluded individuals in their 20s (20-29 years) from the sample population. Because younger people are less inclined to use TKM as frequently than older people, these studies were likely to report higher proportions compared to other surveys. However, it is certain that the frequency of TKM use has steadily increased over the past 15 years. In this study, TKM use was highly prevalent among older adults. Compared with younger adults, older adults were more likely to visit TKM clinics to cure diseases, receive healthcare, or improve their physical and emotional well-being. As in many other countries, acupuncture was the most commonly used TKM therapy and was associated with the highest reported frequency of improvement. Acupuncture is one of the few CAM therapies that has the advantage of being accepted as modern medicine, most likely because of the volume of scientific evidence supporting it [18,19]. Notably, TKM was preferred by women more than men in South Korea. According to the 2006 survey by Ock et al., females (80.3%) used TKM more commonly than males (69.3%) [14]. In the 2008 survey, more females (53.6%) used TKM than males (46.4%) did [12]. Consistent with previous results, we found that more females (75.3%) than males (65.3%) had positive attitudes toward TKM therapies. Women are also frequent users of CAM in many countries [20][21][22]. Nevertheless, it is difficult to obtain a comprehensive explanation as to why women prefer TKM. The usage of Chuna or physical therapies was found to be less prevalent among the Korean public. In general, the public could not easily distinguish Chunaa type of TKM therapy largely used for balancing orthopedic structure and functionfrom other types of manual therapies [23]. Externally, this practice has a strong similarity to chiropracty. Furthermore, some TKM clinics are performing both of these therapies without informing the patient which therapy is being employed. When educational level is considered with respect to usage of TKM, college graduates were shown more likely to trust Western medicine (73.2%) than TKM (56.9%). However, this result does not coincide with the frequency of TKM use. In CAM surveys in developed Western countries, the educational level of CAM users was reported to be higher than that of non-users [17,[24][25][26][27]. However, other studies have reported that the educational level of CAM users was lower than that of non-users [28] or that educational level was not correlated with CAM usage at all [29,30]. Therefore, the influence of education level on CAM and TKM usage is ambiguous and debatable. Most participants likely trusted TKM because they recognized that TKM includes therapies that have been proven useful over centuries (58.0%) and have been proven to be safe (52.7%) and effective (35.2%).
The year 2008 was considered to be a milestone year for TKM researchers because several significant aspects revealed themselves, including scientific, sociological, and political factors. First, the TKM scientific paradigm has shifted greatly and systemically. TKM research can  This result is important because it clearly shows that attitudes toward TKM have changed to become more positive, perhaps because of the various efforts described above. Our survey has several limitations, one of which is a geographical limitation. We collected our data from individuals living in five large metropolitan cities in South Korea, distributed evenly across the country: Seoul, Daejeon, Daegu, Pusan, and Gwangju. Given that this survey was the first cross-sectional study since the 2008 survey, some differences between the two surveys were found. First, Shin et al. combined two different survey methods, with the majority conducted online and a minority conducted as face-to-face interviews, whereas in the current study, we employed a single online survey. Second, the size of their sample was double the size of ours. Third, the author of the 2008 survey was focused on the occurrence of adverse events in TKM. Taken together, these differences may have limited the precision of the estimations in the study [12], and, because this study was a retrospective survey, it has the potential for recall bias. The results may also have been affected by selection bias. In addition, because we did not test the validity and reliability of our instrument, our data may contain inaccurate results. However, we tried our best to minimize possible errors/biases from the questionnaire via numerous meetings with Dr. HK Shin [12]. Nevertheless, this study is meaningful because it is the first to assess defined TKM usage by excluding non-traditional Korean modalities according to socio-demographic characteristics. Furthermore, this study is the first attempt to analyze changing trends in TKM consumption by combining its analysis and data with data from previous surveys.

Conclusions
In this study, we used data from 2011 to identify the factors that determine TKM usage. Additionally, this study revealed that the attitude toward and usage of TKM have improved between 2008 and 2011. We suggest that the popularity of TKM can be attributed to various factors, including a paradigm shift in scientific fields, an expansion of TKM infrastructure, and unwavering support from the government since 2008. The findings are valuable when interpreting the outcomes of social phenomena and constitute a good source for demonstrating the importance and necessity of national support to promote TKM.