Background
Numerous studies in various countries attest to the high frequency of low back pain (LBP). Approximately 70-85% of all people have back pain at some point in their lifetime, and the annual prevalence ranges from 15% to 45%, with point prevalence averaging 30%. Nearly 80-90% of patients with back pain recover quickly within 12 weeks, but recovery after 12 weeks is slow and uncertain[
1]. Chronic LBP is defined as LBP that persists or recurs over 12 weeks [
1,
2]. A 2007 Korean National Health and Nutrition Survey (KNHNS) data analysis showed that over 6.5% of adults experience chronic LBP [
3]. Chou et al. [
4] stated that there has been little consensus on the management of LBP, and the development of clinical practice guidelines based on available evidence is necessary.
In some countries, the addition of acupuncture treatment, compared to usual care alone, has proved to be cost-effective [
5,
6]. However, some parameters, such as natural mortality rates, medical costs and national threshold, which are necessary in the analyses, differ from country to country. Therefore, cost-effectiveness results may also vary by medical institution and conditions; an economic evaluation should be conducted for each situation [
7].
Decision analytic modelling is a systematic approach to decision making under uncertainty that is widely used in economic evaluations of pharmaceuticals and other health care technologies [
7]. Despite the concerns about the methodologies of economic evaluation [
8], decision analytic modelling is used to synthesise the best available data and conduct economic evaluations, especially when no optimal cost-effective analytic outcome from clinical trials has yet been established [
9].
Recently, the Korean Ministry of Health, Welfare and Family Affairs (MOHW) launched several laws concerning medical provider employment and collaboration. Under these laws, doctors and Oriental medical doctors (acupuncture qualified) can work together in the same facility and offer collaborative treatment at the same time for the same disease [
10]. Until 2009 in South Korea, these types of collaborations were indirectly regulated by the limited reimbursing regulation of Health Insurance Review and Assessment service (HIRA). Therefore, there is a possible increase in chronic LBP cases that are treated with collaborative treatment in addition to the usual practice.
The purpose of this study is to examine the cost-effectiveness of usual care and acupuncture collaboration as compared to usual care alone, and to provide information about the level of improvement required to substantially alter the cost-effectiveness of the therapeutic decision in South Korea. We also conducted a value of information analysis, using the net monetary benefit and population expected value of perfect information (EVPI), to provide a rational background for future research investments.
Discussion
Recently, an increasing number of clinical research concerning acupuncture for LBP has been conducted in various countries [
5,
25,
29‐
35]. In these papers, the results do not provide firm conclusions about the effectiveness of acupuncture for acute LBP. However, for chronic LBP patients, acupuncture was assumed to be effective for pain relief and functional improvement [
15‐
17,
36]. Furland et al. in their systematic review, concluded that acupuncture may be a useful adjunct to other therapies for chronic LBP [
15]. However, reimbursement agents such as governments and insurers have recently required evidence of economic benefit along with clinical benefits to cover the treatments.
In 2010, the South Korean MOHW introduced several laws regarding medical provider employment and collaboration, which allow medical doctors and Oriental medical doctors (acupuncture qualified) to work together in the same facility and offer simultaneous collaborative treatment for the same disease. Previously, these types of collaborations were indirectly regulated by the limited reimbursing regulation of HIRA. These regulation changes will increase the frequency of collaboration between medical doctors and Oriental medical doctors; however, whether the national health insurance will cover this system is yet to be determined.
Therefore, we conducted this study to evaluate a collaboration of acupuncture and usual care for chronic LBP patients in the newly developing medical environments of South Korea.
Prior studies on this subject using patient level data have been published in other countries. In the UK, Ratcliffe and colleagues [
6] conducted a pragmatic randomised clinical trial (RCT) and examined the cost-effectiveness of the addition of acupuncture treatment compared to usual care alone. They calculated the ICER of acupuncture at 24 months as £4,241 per QALY (1£ = 1,944.16 KRW). They concluded that assuming an implicit threshold of a maximum of willingness to pay of £20,000 per QALY, collaboration offers a modest health benefit for a minor extra cost to the National Health Service (NHS).
Witt et al. [
5] also published pragmatic RCT results in Germany. In their study, they employed three arms of a mixed model, two arms of randomised groups, and one observational group, which were utilised to avoid the selection bias of participant inclusion. If the participants with severe LBP did not enter into the study and attempt to be treated by most available treatments, then the results would be exposed to a selection bias. Therefore, in the analysis, the researchers were able to examine the selection bias by comparing characteristics of randomised and non-randomised groups. Their results showed that the ICER of acupuncture was €10,526 per QALY (1€ = 1,742.12 KRW), and they concluded that acupuncture collaboration was relatively cost-effective at the threshold of €50,000.
These cost-effectiveness results, which are thought to be based on different medical institutions and economic conditions, could not be extrapolated to other countries. Hutubessy et al addressed that the simple extrapolation would be easy and quick, but it would result in misleading answers and could encourage inefficient decisions [
37].
While the two studies mentioned above conducted the analyses using patient-level data from pragmatic RCTs, we used a Markov model simulation to obtain the discounted QALYs as a measure of effectiveness. The Markov model format allowed us to evaluate the economic impact of both alternatives over a five-year time horizon. The state definitions of chronic LBP in previous clinical trials were somewhat varying and confusing according to the purpose of each research. Therefore, we defined chronic LBP as persistent pain for 12 weeks or more, based on the clinical practice guidelines published by the Agency for Health Care Policy and Research (AHCPR) [
38] and the Questionnaire of KNHNS 2007 [
3].
The definition of 'usual care' could also vary based on each country's medical system. Although 54 clinical practice guidelines developed from South Korean medical system were listed in the official database, the specific guidelines for chronic LBP had not been established [
39]. Therefore, we developed the questionnaire of usual care intervention lists from the ACP&APS' pharmacologic and non-pharmacologic interventions which are registered in the international practice guideline database [
40]. Then we asked orthopaedic and rehabilitation specialists from a general hospital to identify the commonly using procedures in South Korea. Based on the survey results, we defined NSAIDs, heat therapy, electrotherapy and lumbar traction as the 'usual care' in South Korea.
The effectiveness of additive acupuncture treatment compared with usual care was derived from the improvement of state QOL of chronic LBP and changed transition probability to the Well state. The state QOL of chronic LBP treated with both alternatives was derived from the Witt et al. study results [
5], and the difference of transition probabilities to the Well state was assumed from meta-analysis.
Although the effects come at a high cost, resulting in a marginal cost effectiveness ratio of nearly 3,421,394 KRW per QALY, the costs are less than the generally accepted societal threshold for willingness to pay at 20,000,000 KRW per QALY. In the probabilistic sensitivity analysis, there was a 72.3% chance that collaborative treatment would be cost-effective at a willingness to pay threshold of 20,000,000 KRW per QALY. This result indicates that for chronic LBP disease, acupuncture collaborative treatment could be acceptable to the National Health Insurance reimbursement lists.
Several limitations of the present analysis should be considered when interpreting its results. First, we could not include all available alternatives due to a lack of evidence. Despite the fact that herbal medicines, cupping, and other treatments are commonly used as alternative treatments in South Korea, we could not find appropriate papers that analysed the effectiveness of these alternatives. However, Weinstein et al. wrote that the ability of the model to make accurate predictions of future events is valuable, but not absolutely essential [
13]. Because future events convey information that is not available at the time the model is developed, a model should not be criticised for failing to predict the future. Therefore, if these or other interventions establish evidences of their own effectiveness, we will take this new evidence into account for future analyses.
Second, the uncertainties of parameters in the Markov model could not be ruled out. Although, we examined the validation with a calibration, the uncertainty could not be solved perfectly. If future epidemiologic studies of the Korean population are published, then we could develop our model with more precision.
Third, when constructing the model of disease progression, the 'memoryless problem' of the Markov assumption could not be solved. When developing the model, the severity of disease that could differ in accordance with the disease progression should be considered using tunnel states. In addition, as mentioned in the Grotel et al. study, psychological, social and economic factors that differ among other countries could affect the chronification of LBP should also be considered in the modelling [
21]. However, we could not find any appropriate data for building the tunnel state in the model.
Fourth, we could not avoid the discrepancy of evidence levels. In the cases of direct non-medical costs and usual care intervention lists, we had to depend on the low-level evidence of specialists' responses and simple hospital cost data.
Fifth, the heterogeneity of the data may affect the ability to generalise our findings. We used other countries' data for the meta-analysis, which could be a caveat to the full interpretation of effectiveness.
Despite these limitations, we built the Markov model of chronic LBP and conducted a cost-effectiveness analysis of usual care and acupuncture collaboration according to the reference case analysis methods. Finally, this study may offer evidence of allocative efficiency concerning the collaborative treatment of chronic LBP in the 2010 Korean medical environment.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
NKK was responsible for developing the research and drafting the manuscript. NKK originated the idea for this study and contributed to all phases of research and writing. In addition, he analysed and interpreted the data for study. TJL, BMY, and SMK participated in the analysis and interpretation of data, in the critical revision of the manuscript for important intellectual content, and in the study supervision. All authors reviewed and approved the final version of this manuscript.