Abstract: We included seven studies from the literature search, but only six provided sufficient data for analyses. Included studies were European, cluster RCTs with adult participants seeing their usual doctor (in total 233 general practitioners and 1787 participants). Methodological quality was only moderate as studies had no blinding of healthcare professionals and several studies had a risk of recruitment and attrition bias. Studies were heterogeneous with regard to selection of patient populations and intensity of interventions. Outcomes relating to physical or general health (physical symptoms, quality of life) showed substantial heterogeneity between studies (I2 > 70%) and post hoc analysis suggested that benefit was confined to more intensive interventions; thus we did not calculate a pooled effect. Outcomes relating to mental health showed less heterogeneity and we conducted meta-analyses, which found non-significant overall effect sizes with SMDs for changes at 6 to 24 months follow-up: mental health (3 studies) SMD -0.04 (95% CI -0.18 to 0.10), illness worry (3 studies) SMD 0.09 (95% CI -0.04 to 0.22), depression (4 studies) SMD 0.07 (95% CI -0.05 to 0.20) and anxiety (2 studies) SMD -0.07 (95% CI -0.38 to 0.25). Effects on sick leave could not be estimated. Three studies of patient satisfaction with care all showed positive but non-significant effects, and measures were too heterogeneous to allow meta-analysis. Results on healthcare utilisation were inconclusive. We analysed study discontinuation and found that both short term and long term discontinuation occurred more often in patients allocated to the intervention group, RR of 1.25 (95% CI 1.08 to 1.46) at 12 to 24 months. Current evidence does not answer the question whether enhanced care delivered by front line primary care professionals has an effect or not on the outcome of patients with functional somatic symptoms. Enhanced care may have an effect when delivered per protocol to well-defined groups of patients with functional disorders, but this needs further investigation. Attention should be paid to difficulties including limited consultation time, lack of skills, the need for a degree of diagnostic openness, and patient resistance towards psychosomatic attributions. There is some indication from this and other reviews that more intensive interventions are more successful in changing patient outcomes.

Plain-language summary: The review found that the relevant six studies varied in significant ways: how severe the patients’ symptoms were; the form and intensity of the enhanced care offered. These differences made the studies difficult to compare. Many people left the studies before the outcomes could be measured. Given these problems with comparing existing research, it is only possible to say: enhanced care may help people with functional somatic symptoms; more intensive enhanced care may be more effective than very brief interventions. Further research into this topic is needed to test how much and what type of enhanced care could be effective. Future research should take into account barriers that might prevent such treatments benefitting patients. These include: GPs’ lack of time or skills, and their low expectations that enhanced care might help patients; patients’ reluctance to accept non-physical understandings of somatic symptoms.