Cancer patients’ use of complementary and alternative medicine in Sweden: a cross-sectional study

Complementary and Alternative Medicine (CAM) is a broad set of non-mainstream practices including use of natural products, mind-body therapies and entire medical systems [1]. Use among cancer patients has increased in the last decades [2]. National and regional heterogeneity, gender, age, education and type of tumor appear to influence usage patterns and frequency [2‐4]. Research on both effectiveness and risks of specific CAM modalities for cancer patients accumulates [5] and attempts to establish evidence-based clinical guidelines are made [6] and have recently been endorsed by the American Society of Clinical Oncology [7]. Open communication between patients and cancer care providers (beneath referred to as providers) has been valued essential to meet patients´ needs and to improve understanding regarding direct risks as well as to prevent indirect risks [8]. The authors of several studies [9‐12] highlight the need of an improved dialogue concerning CAM. Leading comprehensive cancer centers [13] provide the concept of integrative oncology [14] as a patient-centered health care model to meet patients’ preferences, to ensure their safety and to optimize clinical outcomes [15‐18]. Other authorities have established research centers and scientific information services about CAM [1, 19].

Previous studies on Swedish cancer patients’ CAM use have mainly focused on natural products [20] and specific groups of patients [10, 20] and indicate similar usage frequency as other high-income countries. Research on Swedish professionals´ perceptions of CAM indicate uncertainty about evidence, indications, contraindications and skepticism about high costs [21‐23] .

Practice of evidence-based medicine requires integrating individual clinical expertise, patient values and circumstances with the best available external clinical evidence from systematic research [24]. To understand patient values and circumstances in relation to CAM it is crucial to study usage across different countries and cultures. This cross-sectional study builds on previous surveys to advance the view of cancer patients’ CAM use in general, focusing on Swedish cancer patients’ experiences and preferences.

This study describes CAM use and related experiences among Swedish patients with solid tumors in both curative and palliative stage. One third (34%) of participants had used CAM at some point in their life and 26% after cancer diagnosis. This is in line with previous studies, e.g. a European study where CAM use was reported by 36% [3], without distinction between use before or after cancer diagnosis. The similarity to our findings is surprising as access to and advice on CAM modalities are generally low within cancer care in Sweden, due to Swedish regulations requiring health personnel to practice in accordance with “science and experiential knowledge” [27, 28]. Since patients in this study visited an oncological department, CAM seems to be mainly used complementary and not alternatively to conventional therapy. This also corresponds to participants´ free-text responses where they specify reasons for and benefits from CAM use.

In line with international [3, 29, 30] and other Scandinavian surveys [4, 9], we found statistically significant relationships between CAM use and being female, younger and higher educated. These results may suggest high health literacy among CAM users and a gender aspect of unmet needs in conventional care.

In agreement with previous results [3, 31] we found that patients used and combined a diversity of CAM modalities. Natural products and mind-body therapies were most popular. This concurrent and multimodal use implies an immense challenge for research and practice in regard to interactions [32], efficacy and educational needs among patients as well as providers in a pluralistic context [33].

In our study, 5.6% of CAM users reported mild and transient adverse effects (mostly gastrointestinal discomfort) from a CAM modality, which was mainly related to intake of natural products, as shown earlier [3, 9, 34]. Participants’ detailed specifications related to their experiences of CAM use as well as previous results on patients´ concerns about risks for interactions [35] indicate that many CAM users pay close attention to both positive and negative consequences of their CAM use. Thus, patients seem to be a potential and possibly underestimated resource for monitoring of adverse effects and effectiveness, as also acknowledged by the introduction of PROM/PREM in evaluating clinical trials. Therefore, an open and trustful dialogue between patients and providers is fundamental. However, in our study only 2% of No CAM users and 33% of CAM users had discussed CAM modalities with their provider, i.e. less than in recent Scandinavian literature [9, 10, 34]. The results from these previous studies indicate that around 50% of patients have a dialogue about CAM. Consequently, up to 67% of CAM use in our study may be unknown to providers representing both potential risks and undiscovered possibilities. Since CAM users were more likely to have discussed CAM compared to No CAM users, this dialogue was usually patient initiated, suggesting a threat to patient safety. For example, it has been shown previously that physicians who are perceived to be poorly informed or negative about CAM induce safety concerns in terms of e.g. potential undiscovered interactions as well as patient anxiety [35].

Two thirds (67%) of CAM users and 49% of No CAM users (Table 6) thought that providers should have enough knowledge to be able to answer questions on CAM; which has been shown earlier [11, 35]. However, conventional health care was the least common source of information about CAM modalities while media, family or friends and internet were most commonly used; as previously reported [31, 34] and highlighting the need for quality assured information. Our findings are not surprising since Swedish health care professionals still report lack of knowledge about CAM [11, 21, 36‐38]. Better knowledge is known to increase dialogue [21‐23].

The main reasons for CAM use were to improve well-being and to increase the body’s ability to fight cancer, i.e. not to fight cancer per se. Benefits were reported as being mostly physical and emotional. Both reasons for use and perceived benefits were often multifaceted, e.g. a single CAM modality was used and perceived efficacious both for improving emotional well-being and reducing adverse effects of conventional treatment. Notably, fighting cancer was rarely given as a reason for CAM use. These results correspond to earlier research indicating complex motives for CAM use [39‐43], shifting motives over time [34, 44] and benefits not always related to initial reasons for use [3, 8, 30]. Also, in line with previous findings, [3] patients in this study reported high satisfaction with CAM (87%) and the majority of users considered CAM being worth the money (91% of CAM users). Moreover, 71% of CAM users and 48% of No CAM users considered that CAM modalities should be offered within conventional cancer care and participants stressed the importance of scientific evidence, competence and quality of CAM. While patients’ satisfaction with care - conventional or CAM - is multifaceted and clearly needs to be considered together with other aspects of evidence, as also patients argue in their responses, the high satisfaction rates among CAM users found here needs to be considered by decision makers in cancer care.

Strengths of this study include the cross-sectional design with three different data collection sites and the large sample size. These factors help ensure representativity for cancer patients with solid tumors in urban Sweden, although the results may not be fully transferable to more rural areas. The questionnaires were completed anonymously, and responses could not be linked to electronic health records or sociodemographic variables; thus, participants’ diagnoses and socio-demographics are exclusively self-reported. Self-selection bias potentially attracting CAM users to participate to a larger extent than No CAM users is however unlikely since gender proportions were similar in visits to the clinic and responses to the questionnaire. If CAM users had been more likely to respond to the questionnaire, there would be an overrepresentation of women among responders since female patients represented 80% of CAM users in our material.

Strengths with the questionnaire, although not formally validated, were that an earlier version had been previously used in a large European survey, and that space was given for additional free-text responses. The recruitment of participants at their follow-up visit at the oncology department might explain somewhat lower CAM use compared with previous studies. Terminally ill patients were not represented and in general, participants might have been reluctant to admit CAM use while waiting for conventional oncological care. The response rate of 58% could be seen as a limitation of the study and a higher response rate would have been desirable, however, it is in line with previously published CAM surveys [45].

To conclude, the results here suggest that at least one fourth of Swedish cancer patients use CAM, are highly satisfied with this use, generally have reasonable expectations and are alert to the consequences. Therefore, our results point to an urgency of research on CAM and an informed professional practice to ensure patient safety and satisfaction. Cancer care professionals need to be able to discuss CAM based on the three principles of evidence-based medicine (patients’ values, professional experience, current research). Swedish cancer care needs a strategy for research and education about CAM to integrate CAM modalities with shown beneficial value for patients and to avoid possibly harmful CAM. The concept of integrative oncology [14] may provide a professional solution both regarding providers´ and patients’ needs.