Self-help for medically unexplained symptoms: a systematic review and meta-analysis

Background: Medically unexplained symptoms (MUS), which are highly prevalent in all fields of medicine, are considered difficult to treat. The primary objective of this systematic review and meta-analysis was to assess the efficacy of self-help for adults with MUS. Methods: Four electronic databases were searched for relevant studies. Randomized controlled trials comparing self-help to usual care or waiting list in adults with MUS were selected. Studies were critically appraised using the Cochrane ‘risk of bias assessment tool’. Standardized mean differences (Hedges’ g) were pooled using a random-effects model. Outcomes were symptom severity and quality of life (QoL) directly post-treatment and at follow-up. Results: Out of 582 studies identified, 18 studies met all inclusion criteria. Studies were heterogeneous with regard to patient populations, intervention characteristics, and outcome measures. Compared to usual care or waiting list, self-help was associated with lower symptom severity (17 studies, n = 1894, g = 0.58, 95% CI 0.32 – 0.84, p < .001) and higher QoL (16 studies, n = 1504, g = 0.66, 95% CI 0.34 – 0.99, p < .001) directly post-treatment. Similar effect sizes were found at follow-up. A high risk of bias was established in the majority of included studies. However, sensitivity analyses suggested that this did not significantly influence study results. Funnel plot asymmetry indicated potential publication bias. Conclusions: Self-help is associated with a significant reduction in symptom severity and improvement of QoL. Due to the suboptimal methodological quality of included studies, further research is needed to confirm the findings of this study. INTRODUCTION Medically unexplained symptoms (MUS) are physical symptoms, which cannot be adequately explained by organic disease. MUS are highly prevalent and range from single, self-limiting complaints to constellations of chronic and disabling symptoms like irritable bowel syndrome (IBS), fibromyalgia, and chronic fatigue syndrome (CFS) (1). Apart from the suffering and impairments these conditions impose on patients, they are also very costly for society due to the associated productivity losses and burden on health care (2-4). Patients with MUS visit their general practitioner, medical specialist, and emergency department approximately twice as often as other patients (2), ranking their medical costs among the highest of all patient groups (4). Physicians consider patients with chronic MUS among the most difficult patients (5), probably because treatment possibilities within somatic healthcare are limited (6). Psychological treatments, like cognitive behavioral therapy (CBT), have shown modest effects on symptom severity and quality of life (QoL) in patients with chronic MUS (7, 8). However, psychological treatments are costly, time consuming, and often not easily available due to a shortage of qualified therapists. Furthermore, many patients with MUS are unwilling to visit a mental health professional, because of the associated stigma (9). As a consequence, only a selected subgroup of patients with MUS benefits from psychological treatment. Self-help interventions, which are designed to be conducted largely independently of health care professionals, might overcome these problems and form a valuable addition to current treatment options. Self-help has shown to be effective for a number of conditions like depression, anxiety, and alcohol abuse (10-12). Apart from three systematic reviews on specific forms of self-help for IBS (13-15), no overview has been published on the efficacy of self-help interventions for MUS in general. Following the PRISMA statement (16), we report on a systematic review and meta-analysis of randomized controlled trials with the primary aim of assessing efficacy of self-help in adults with MUS with regard to symptom severity and QoL. Because we included a variety of MUS, investigating whether treatment efficacy varied according to the type of symptoms was a secondary aim. Studies in patients with depression and anxiety have indicated that guided self-help is associated with better outcomes than unguided self-help (17, 18). Therefore, another secondary aim was to study the influence of therapist contact on treatment efficacy. Self-help for Medically Unexplained Symptoms | 43