Background: The term 'medically unexplained symptoms' is used to cover a wide range of persistent bodily complaints for which adequate examination and appropriate investigations do not reveal sufficiently explanatory structural or other specified pathologies. A wide range of interventions may be delivered to patients presenting with medically unexplained symptoms in primary care. Many of these therapies aim to change the behaviours of the individual who may have worsening symptoms.
Objectives: An evidence synthesis to determine the clinical effectiveness and cost-effectiveness of behavioural modification interventions for medically unexplained symptoms delivered in primary care settings was undertaken. Barriers to and facilitators of the effectiveness and acceptability of these interventions from the perspective of patients and service providers were evaluated through qualitative review and realist synthesis.
Data sources: Full search strategies were developed to identify relevant literature. Eleven electronic sources were searched. Eligibility criteria - for the review of clinical effectiveness, randomised controlled trials were sought. For the qualitative review, UK studies of any design were included. For the cost-effectiveness review, papers were restricted to UK studies reporting outcomes as quality-adjusted life-year gains. Clinical searches were conducted in November 2015 and December 2015, qualitative searches were conducted in July 2016 and economic searches were conducted in August 2016. The databases searched included MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO and EMBASE. Updated searches were conducted in February 2019 and March 2019.
Participants: Adult participants meeting the criteria for medically unexplained symptoms, including somatoform disorders, chronic unexplained pain and functional somatic syndromes.
Interventions: Behavioural interventions were categorised into types. These included psychotherapies, exercise-based interventions, multimodal therapies (consisting of more than one intervention type), relaxation/stretching/social support/emotional support, guided self-help and general practitioner interventions, such as reattribution. Evidence synthesis: a network meta-analysis was conducted to allow a simultaneous comparison of all evaluated interventions in a single coherent analysis. Separate network meta-analyses were performed at three time points: end of treatment, short-term follow-up (< 6 months since the end of treatment) and long-term follow-up (≥ 6 months after the end of treatment). Outcomes included physical and psychological symptoms, physical functioning and impact of the illness on daily activities. Economic evaluation: within-trial estimates of cost-effectiveness were generated for the subset of studies where utility values (or quality-adjusted life-years) were reported or where these could be estimated by mapping from Short Form questionnaire-36 items or Short Form questionnaire-12 items outcomes.
Results: Fifty-nine studies involving 9077 patients were included in the clinical effectiveness review. There was a large degree of heterogeneity both between and within intervention types, and the networks were sparse across all outcomes. At the end of treatment, behavioural interventions showed some beneficial effects when compared with usual care, in particular for improvement of specific physical symptoms [(1) pain: high-intensity cognitive-behavioural therapy (CBTHI) standardised mean difference (SMD) 0.54 [95% credible interval (CrI) 0.28 to 0.84], multimodal SMD 0.52 (95% CrI 0.19 to 0.89); and (2) fatigue: low-intensity cognitive-behavioural therapy (CBTLI) SMD 0.72 (95% CrI 0.27 to 1.21), relaxation/stretching/social support/emotional support SMD 0.87 (95% CrI 0.20 to 1.55), graded activity SMD 0.51 (95% CrI 0.14 to 0.93), multimodal SMD 0.52 (95% CrI 0.14 to 0.92)] and psychological outcomes [(1) anxiety CBTHI SMD 0.52 (95% CrI 0.06 to 0.96); (2) depression CBTHI SMD 0.80 (95% CrI 0.26 to 1.38); and (3) emotional distress other psychotherapy SMD 0.58 (95% CrI 0.05 to 1.13), relaxation/stretching/social support/emotional support SMD 0.66 (95% CrI 0.18 to 1.28) and sport/exercise SMD 0.49 (95% CrI 0.03 to 1.01)]. At short-term follow-up, behavioural interventions showed some beneficial effects for specific physical symptoms [(1) pain: CBTHI SMD 0.73 (95% CrI 0.10 to 1.39); (2) fatigue: CBTLI SMD 0.62 (95% CrI 0.11 to 1.14), relaxation/stretching/social support/emotional support SMD 0.51 (95% CrI 0.06 to 1.00)] and psychological outcomes [(1) anxiety: CBTHI SMD 0.74 (95% CrI 0.14 to 1.34); (2) depression: CBTHI SMD 0.93 (95% CrI 0.37 to 1.52); and (3) emotional distress: relaxation/stretching/social support/emotional support SMD 0.82 (95% CrI 0.02 to 1.65), multimodal SMD 0.43 (95% CrI 0.04 to 0.91)]. For physical functioning, only multimodal therapy showed beneficial effects: end-of-treatment SMD 0.33 (95% CrI 0.09 to 0.59); and short-term follow-up SMD 0.78 (95% CrI 0.23 to 1.40). For impact on daily activities, CBTHI was the only behavioural intervention to show beneficial effects [end-of-treatment SMD 1.30 (95% CrI 0.59 to 2.00); and short-term follow-up SMD 2.25 (95% CrI 1.34 to 3.16)]. Few effects remained at long-term follow-up. General practitioner interventions showed no significant beneficial effects for any outcome. No intervention group showed conclusive beneficial effects for measures of symptom load (somatisation). A large degree of heterogeneity was found across individual studies in the assessment of cost-effectiveness. Several studies suggested that the interventions produce fewer quality-adjusted life-years than usual care. For those interventions that generated quality-adjusted life-year gains, the mid-point incremental cost-effectiveness ratios (ICERs) ranged from £1397 to £129,267, but, where the mid-point ICER fell below £30,000, the exploratory assessment of uncertainty suggested that it may be above £30,000.
Limitations: Sparse networks meant that it was not possible to conduct a metaregression to explain between-study differences in effects. Results were not consistent within intervention type, and there were considerable differences in characteristics between studies of the same type. There were moderate to high levels of statistical heterogeneity. Separate analyses were conducted for three time points and, therefore, analyses are not repeated-measures analyses and do not account for correlations between time points.
Conclusions: Behavioural interventions showed some beneficial effects for specific medically unexplained symptoms, but no one behavioural intervention was effective across all medically unexplained symptoms. There was little evidence that these interventions are effective for measures of symptom load (somatisation). General practitioner-led interventions were not shown to be effective. Considerable heterogeneity in interventions, populations and sparse networks mean that results should be interpreted with caution. The relationship between patient and service provider is perceived to play a key role in facilitating a successful intervention. Future research should focus on testing the therapeutic effects of the general practitioner-patient relationship within trials of behavioural interventions, and explaining the observed between-study differences in effects within the same intervention type (e.g. with more detailed reporting of defined mechanisms of the interventions under study).
Study registration: This study is registered as PROSPERO CRD42015025520.
Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 46. See the NIHR Journals Library website for further project information.
Keywords: BEHAVIOUR THERAPY; CHRONIC FATIGUE SYNDROME; COGNITIVE–BEHAVIOURAL THERAPY; EXERCISE THERAPY; FIBROMYALGIA; FUNCTIONAL DISORDERS; GENERAL PRACTICE; GRADED ACTIVITY; IRRITABLE BOWEL SYNDROME; MEDICALLY UNEXPLAINED SYMPTOMS; PRIMARY CARE; REATTRIBUTION.
The term ‘medically unexplained symptoms’ is used in relation to individuals who present to their general practitioner with persistent symptoms that cannot easily be explained, even after adequate physical examination and appropriate investigations. Common interventions delivered in primary care tend to be psychological interventions, behaviour therapies or physical exercise therapies. These therapies often aim to change the behaviours of the individual that may make symptoms worse. We conducted systematic reviews of existing evidence to evaluate the effectiveness and acceptability of behavioural interventions delivered in primary care, and a cost-effectiveness analysis to see whether or not they offer good value. Studies measured improvement in outcomes, such as physical or psychological symptoms, or health-related quality of life. There were large differences in the nature of the behavioural interventions delivered and so we grouped them into ‘types’. These included intervention types involving exercise (e.g. aerobic or strengthening, or graded activity); different types of psychotherapy, for example cognitive–behavioural therapy; interventions focused on relaxation or social/emotional support; interventions offering education and information; and interventions by general practitioners, for example receiving training on how to implement a behavioural approach to treating medically unexplained symptoms. Statistical analyses were conducted to investigate which, if any, of the intervention types were effective when compared with usual care. Results indicated that some of the behavioural intervention types showed beneficial effects at the end of treatment and at short-term follow-up. In particular, cognitive–behavioural therapy at a higher intensity, and therapies consisting of components of more than one intervention type (i.e. multimodal therapies), showed beneficial effects for specific physical symptoms such as pain, fatigue or bowel symptoms. High-intensity cognitive–behavioural therapy, other types of psychotherapies and interventions focusing on relaxation and social/emotional support showed some beneficial effects on mood outcomes such as depression and anxiety. By long-term follow-up, effects had diminished. More complex measures of symptom load or ‘somatisation’ showed fewer beneficial effects. We found that no one intervention improved outcomes across all medically unexplained symptoms. However, the results of the statistical analyses should be interpreted with caution. Not only were there differences in the types of behavioural interventions trialled in the included studies, but there were also differences in the characteristics of interventions within the same type. Participants of the studies had a range of symptoms and syndromes, of varying severity and duration. Interventions of the same type varied in how they were delivered, for example the qualifications of the therapist and the contact time spent between therapist and patient. Owing to the limited number of studies in each intervention type, it has not been possible to identify how these differences influenced the results. Interventions delivered by general practitioners themselves did not generally show beneficial effects. However, the relationship between general practitioner and patient was perceived to be important. Patients valued receiving explanations for their symptoms and learning self-management techniques. This was facilitated by good relationships with their health-care practitioner. Health-care practitioners reported a need for training and supervision, but patients reported that the primary care setting was both appropriate and helpful. A successful behavioural intervention should allow a patient and their care provider to maintain a relationship where the patient feels supported. Analyses of the cost-effectiveness of the interventions showed a wide variation in costs. Costs varied between different intervention types, but also between interventions of the same type. Differences in the nature of interventions within the same intervention type, for example whether delivery is to groups or to individuals, make comparisons difficult. Future research should focus on identifying how the relationship between the general practitioner and their patient can influence the effectiveness of a behavioural intervention when it is conducted in the primary care setting. In addition, more research is needed to explore which aspects of the more promising interventions are influencing their effectiveness.