Prevalence, specific and non-specific determinants of complementary medicine use in Switzerland: Data from the 2017 Swiss Health Survey

Objectives To determine the prevalence of use of complementary medicine (CM) in Switzerland in 2017, its development since the 2012 Swiss Health Survey, and to examine specific and non-specific sociodemographic, lifestyle and health-related determinants of CM use as compared to determinants of conventional health care use. Materials and methods We used data of 18,832 participants from the cross-sectional Swiss Health Survey conducted by the Swiss Federal Statistical Office in 2017 and compared these data with those from 2012. We defined four CM categories: (1) traditional Chinese medicine, including acupuncture; (2) homeopathy; (3) herbal medicine; (4) other CM therapies (shiatsu, reflexology, osteopathy, Ayurveda, naturopathy, kinesiology, Feldenkrais, autogenic training, neural therapy, bioresonance therapy, anthroposophic medicine). Independent determinants of CM use and of conventional health care use were assessed using multivariate weighted logistic regression models. Results Prevalence of CM use significantly increased between 2012 and 2017 from 24.7% (95% CI: 23.9–25.4%) to 28.9% (95% CI: 28.1–29.7%), respectively, p<0.001). We identified the following independent specific determinants of CM use: gender, nationality, age, lifestyle and BMI. Female gender and nationality were the most specific determinants of CM use. Current smoking, being overweight and obesity were determinants of non-use of CM, while regular consumption of fruits and/or vegetables and regular physical activity were determinants of CM use. Conclusion Prevalence of CM use significantly increased in Switzerland from 2012 to 2017. Gender, nationality, age, lifestyle and BMI were independent specific determinants of CM use as compared to conventional health care use. Healthier lifestyle was associated with CM use, which may have potentially significant implications for public health and preventive medicine initiatives. The nationality of CM users underlines the role of culture in driving the choice to use CM but also raises the question of whether all populations have equal access to CM within a same country.


The flow diagram similar to PRISMA flow chart: would have made the data inclusion more clear.
The data inclusion is described in lines 100 to 105. We included all participants who returned the questionnaire given that information about CM use was only available in the written questionnaire (i.e. 18,882 participants out of 22,134). Therefore, we do not feel that this information would be better depicted by a flow diagram as the data come from a national survey. Other studies based the same database also did not present a flowchart (e.g. https://pubmed.ncbi.nlm.nih.gov/33563620/; https://www.sciencedirect.com/science/article/pii/S221133552200122X). We hope that the reviewer agrees with our reasoning. Any type of complementary medicine is defined as participants who used osteopathy and/or naturopathy and/or homeopathy and/or herbal medicine and/or acupuncture and/or Shiatsu/reflexology /or Traditional Chinese medicine and/or Ayurveda /or other therapies in the past 12 months. Therefore, each participant could have been allocated to several CM therapies. For example, if a participant used osteopathy and acupuncture, he or she was accounted in the category osteopathy and in the category acupuncture, respectively but once in the category any type of complementary medicine.

3.In
Thus, the variable any type of complementary medicine is not the sum of all types of CM but gives the information how many participants used at least one CM therapy in the past 12 months. We have clarified this information in the legend of the There were 125 missing data (i.e. 125 participants did not answer the question). We clarified this information in the legend of the table 3 (line 225, p.13).

Another important aspect is the duration of use of CM, some individuals use it for short duration for example for some short duration issue like 1-2 days(constipation, diarrhoea, pain ) for 2-3 days. Was there any criteria for inclusion of data based on duration of use of CM.
Unfortunately, the Swiss Health survey did not provide any information on frequency and duration of CM use. We acknowledged this lack of information as a limitation of the study (lines 452-453).

The use of CM it is most of the time not taken after consultation from GP or other expert but is usually taken through recommendation by family members, friends or other acquaintances. Highlighting these sources other than experts would have been interesting as it may have safety issues
We agree with the reviewer on this aspect. Unfortunately, such detailed information was not available in the Swiss health survey and thus we could not further elaborate on it.

Reviewer #2
1. Thank you for the opportunity to review this work. The 2017 and 2012 survey data were large but may be outdated. The authors should be applauded for the effort to conduct add-on questionnaire with a relatively good response rate. Nonetheless, the '85.1%' was based on the 18,832 as the numerator and the 22,134 (but not 43,769) as the denominator. Please clarify and add an overview of the Swiss Health Survey in relationship with this particular study.
The 2017 Swiss health survey is the most recent national health survey currently available in Switzerland. The most recent Swiss health survey dates from 2022 and is currently being conducted. This point has been clarified in the manuscript accordingly (lines 102-103, p. 6). All the details concerning the Swiss Health Survey in relationship with our study are described in lines 93-108, p. 5-6. Table 3 presented the 'Supplemental health insurance for complementary medicine' as a separate finding. Actually, this point could be relatively easy to address by analyzing secondary annual claim data that should be available in the developed high-income country context like Switzerland. This suggested approach not only could provide the 'revealed preferences' of Swiss individuals, but also reduce the unreliable operational definitions of the CM and conventional therapies perceived by the respondents as pointed out below.

The coverage by mandatory basic health insurance seems to be intuitively the main factor of the increased CM use. As such, the analysis and/or discussion should differentiate the marginal effect of individual preferences, given the insurance coverage. When was the CM covered (before 2012 / between 2012-2017 / after 2017)?
CM coverage by basic health insurance was suppressed in 2005, and started again in 2012. Therefore, in 2017 and in the comparison data of 2012, there were no change considering the reimbursement. Meanwhile, only some CM delivered by certified physicians are reimbursed by the mandatory basic health insurance. Meanwhile, it was not possible to differentiate among respondents if they used a CM reimbursed by mandatory basic health insurance or not. For example, a respondent who used TCM could have used it with a physician whose service was reimbursed by the mandatory health insurance or a therapist reimbursed by a supplemental health insurance or by none. Therefore, a secondary analysis did not allow for better information on this specific point. In the Discussion section, we discussed the role of regulations in terms of inclusion of CM in health insurance in European countries with the highest rates of prevalence (lines 406-410, p.27). Additionally, we have clarified the fact that in Switzerland CM can be covered by mandatory basic health insurance or private supplemental health insurance (lines 418-422, p.27).

Line 110-114 presented a series of therapies without clear definitions to the readers (and to the respondents)
. Given the fact that these therapies have been covered by the mandatory basic health insurance, they should be clearly defined, along with whether each of the therapies is fully reimbursable and whether out-of-pocket or copayment is required.
In the written questionnaire, respondents were asked whether they had used the following therapies in the past 12 months: osteopathy (yes/no), naturopathy (yes/no), homeopathy (yes/no), herbal medicine (yes/no), acupuncture (yes/no), shiatsu or reflexology (yes/no), TCM (yes/no), Ayurveda (yes/no), or other therapies such as kinesiology, Feldenkrais, autogenic training, neural therapy, bioresonance therapy and anthroposophic medicine (yes/no). No additional information was available for the participant. Most of these therapies are not covered by the mandatory basic health insurance. Covered are currently: anthroposophic medicine, homeopathy, herbal medicine, and traditional Chinese medicine (TCM)) if delivered by a certified physician. Private complementary insurances cover these therapies if delivered by an accredited therapist. Level of coverage of CM therapies varies between private insurances. As previously explained, it was not possible to differentiate in the questionnaire whether the user was reimbursed by a mandatory or a private health insurance, or out of pocket. This information has now been added and clarified in the section Introduction (lines 58-61, p.4) and in the Discussion section (lines 418-422, p.27).