Association between complementary and alternative medicine use and prolonged time to conventional treatment among Thai cancer patients in a tertiary-care hospital

Introduction

Cancer is the leading cause of death in Thailand, and is also responsible for a majority of the economic burden of disease (Rao et al., 2010). The cancer survival rate in Thailand is lower than in other developed countries (Sriamporn et al., 1995). One factor that contributes to the relatively lower survival rate is a prolonged time until the patient undergoes cancer treatment (Elit, 2015), and reducing this time has become a focus of health policy-making in Thailand (Singh, Pearlman & Kostelecky, 2017). In 2002, Thailand implemented a universal insurance coverage scheme which has helped reduce the financial barrier to accessing treatment. However, insufficient financing remains a potential threat to healthcare service quality and sufficiency (Paek, Meemon & Wan, 2016). Inadequate availability of cancer treatment services is a major, but not exclusive, cause of prolonged wait times for cancer treatment, and many patient-related factors can also delay their accessing healthcare services. For example, impoverishment, distance to the treating center, lack of cancer awareness, and patient preference for complementary and alternative medicine (CAM) may preclude or delay timely access to conventional cancer treatments (Bhosai et al., 2011).

Although CAM is difficult to define, the World Health Organization has loosely defined CAM as “a broad set of health care practices that are not part of that country’s own tradition or conventional medicine and are not fully integrated into the dominant health-care system” (World Health Organization, 2019). The present study focused on CAM treatments that were provided by non-medical personnel and not generally provided at Thai public hospitals.

Several demographic and health factors are associated with CAM use, such as sex, education level, income level, ethnicity, chronic diseases, and cancer (Bishop & Lewith, 2008). Moreover, patterns of CAM use can vary between countries, based on geographic factors, religion, government policy and regulation, and barriers to conventional treatments (Adams et al., 2011; Ellison, Bradshaw & Roberts, 2011; Nahin, Dahlhamer & Stussman, 2010). Previous studies have revealed that many kinds of CAM can benefit select patients (Poonthananiwatkul et al., 2015; Ben-Arye et al., 2015). For example, many herbal medicines can be used in combination with chemotherapy to prevent or ameliorate chemotherapy-related side effects, such as nausea and vomiting (Ohnishi & Takeda, 2015). However, improper use of CAM can also cause unexpected interactions with many prescription drugs (Ulbricht et al., 2008). Misleading claims and false advertising for CAM can also lead patients to select CAM instead of conventional therapy (Kerdpon, 2001), which can ultimately delay access to conventional therapy.

The use of CAM among patients with cancer has been studied by many researchers around the world (Horneber et al., 2011). However, little information is available regarding the relationship between CAM use and accessing conventional therapy among Thai patients with cancer. Thus, the present study aimed to investigate the patterns of CAM use and its association with the time until conventional cancer treatment in Thailand.

Materials and Methods

Results

Between May and December 2018, 426 patients were enrolled, including 192 patients (45.1%) who reported using CAM. Among the 192 patients, 53 patients (27.6%) reported using CAM concurrent with or after conventional treatment. Approximately 33.6% of patients reported that they were satisfied with the CAM therapies, 61.1% reported no noticeable effect, and 5.4% reported that they were disappointed with the CAM therapies. Significant differences according to the use or non-use of CAM were observed in sex, cancer stage, and cancer type (Table 1).

Table 2 shows the details regarding the 26 kinds of CAM that were identified. Approximately 34.3% of these therapies involved unlabeled herbal products with unidentifiable components, and most products were produced as decoctions and infusions. The second most common therapy involved traditional Thai medicine (“Ya Mor Sang” or “Dr. Sang’s medicine”), which is provided for free by a registered traditional Thai medicine practitioner. The provider claims that this product is composed of rice hulls and other herbal plants. Lingzhi mushroom was the third most frequently used therapy. Traditional Chinese medicine accounted for 23.1% of the CAM treatments. None of the patients used meditation or acupuncture.

The patients had a median overall time to conventional treatment of 50 days (interquartile range (IQR): 34.0–89.0 days). Patients who received radiation therapy had a noticeably longer time to conventional treatment (median: 78 days, IQR: 49.5–112.5 days) than patients who underwent surgery (median: 41 days, IQR: 29.0–62.0 days) or patients who received chemotherapy (median: 39 days, IQR: 28.0–64.0 days). Among patients who used CAM before conventional treatment, 20 patients (14.4%) deliberately chose to delay conventional treatment and instead selected CAM. These 20 patients were temporarily lost to follow-up, and had a median delay time of 382 days (IQR: 321.0–640.0 days), with a longest wait time of 2,067 days for a patient who had been selected for chemotherapy.

Table 3 shows the median times to conventional treatment and their associations with various factors. The multivariable analyses revealed that a prolonged time to conventional treatment was significantly associated with receiving radiation treatment, stage IV cancer, any use of CAM, and use of CAM before starting conventional treatment (Data S1).

Discussion

Thailand is one of a handful of middle income countries that freely provides all conventional cancer treatments to all citizens as part of a universal health coverage scheme (Tangcharoensathien et al., 2018). In this context, delays in receiving appropriate cancer treatments, regardless of their reason, can lead to poorer health outcomes and a higher economic burden (Gildea et al., 2017). While some CAM professions and products are regulated by governing bodies in Thailand, most CAM treatments remain informal or unregulated (Pocaphan & Kondo, 2011). Thus, given the availability of many unregulated CAM treatments, it is possible that CAM use might prolong the time to conventional treatment among Thai cancer patients. Very few studies have addressed this issue (Mohd Mujar et al., 2017; Malik & Gopalan, 2002; Johnson et al., 2018; Puataweepong, Sutheechet & Ratanamongkol, 2012), and the present study aimed to explore the relationship between CAM use and the time to conventional cancer treatment.

Previous studies have revealed varying prevalence of CAM use among patients with cancer, which ranged from 24% to 84% (Gross, Liu & Bauer-Wu, 2007; Bold & Leis, 2001; Kelly et al., 2000; Kappauf et al., 2000; Münstedt et al., 1996), although this variation may be related to the target population and the definition of CAM that the researchers used. The present study revealed that 45.1% of the patients reported using CAM, which is moderate relative to the rates from previous studies. However, CAM use was significantly more common among men and patients with stage IV cancer.

Herbal products were the most frequently used CAM, and previous studies have indicated that the classification of herbal medicines and diet supplements should be based on intended use, labeling, preparation, and dosage (Serafini et al., 2012). However, it would be difficult to distinguish between herbal medicines and diet supplements in the present study, as approximately two-thirds of the treatments involved homemade products without proper labeling or appropriate quality control. Furthermore, many treatments had been registered as diet supplements, but were used with the intent to treat the patient’s cancer. Although many patients reported that use of these treatments helped alleviate their symptoms, the use of treatments with low quality or at inappropriate dosages can cause unpredictable adverse effects and interactions with conventional treatments (Pilkington & Boshnakova, 2012; Izzo & Ernst 2009). Thus, there is a need to encourage the safe use of homemade herbal medicines among cancer patients.

The time to receiving radiotherapy was longer than the times to receiving surgery and chemotherapy. This is because our hospital is the only facility in the eastern Thailand that provides radiotherapy services, with only three teletherapy machines available to serve a population of 5,000,000 residents. Therefore, access to radiotherapy appears to remain a crucial problem in eastern Thailand.

Using CAM before conventional treatments was also significantly associated with the time to conventional treatment. Among patients who used CAM treatments, 20 patients (14.4%) had received appointments for conventional treatments but were temporarily lost to follow-up and instead chose to receive CAM treatments. The delay time in that group was remarkably longer than the times to conventional treatment in the other groups, which significantly affected the average time to conventional treatment in the present study. However, other factors may also explain why patients use CAM before conventional treatment, as many patients used CAM as an interim treatment before they could receive conventional treatment. In addition, a prolonged wait for conventional treatment could increase the likelihood that a patient would select CAM. These factors may help explain the association between CAM use and the prolonged time to conventional cancer treatment.

Limitations

The present study has several limitations. First, the rate and pattern of CAM use at our center might be different from those in the general population, as we only evaluated patients who attended hospital appointments, which would exclude patients who select CAM treatments without seeking in-hospital treatment. It is also possible that the use of face-to-face interviews could have influenced the participants’ responses (e.g., based on a desire to not reveal that they had used CAM treatments). Second, various factors could influence the categorization of CAM treatments as herbal products and diet supplements, especially as the ingredients were self-reported and their accuracy is reliant on the patient’s recall. Moreover, traditional medicine practitioners tend to not disclose their formulations, which resulted in a large number of unlabeled products containing unidentifiable ingredients. Third, there remains the possibility that the study might not completely include other factors which could influence the time until treatment (e.g., religions and cultural perspectives). Finally, caution is warranted in inferring a causal relationship between CAM use and time to conventional treatment because data were obtained from a cross-sectional study.

Conclusions

Our findings demonstrated that there is a relatively moderate prevalence of CAM use among Thai cancer patients, with most of the CAM treatments involving homemade herbal products. The use of CAM was significantly associated with a prolonged time to conventional treatment. Nevertheless, these findings do not imply that CAM should be banned for all patients, although healthcare providers should recommend that patients aim to use CAM treatments that are considered safe and will not interfere with conventional treatments.

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