Background Lifestyle interventions for severe mental illness (SMI) are known to have small to modest effect on physical health outcomes. Little attention has been given to patient-reported outcomes (PROs). Aim To systematically review the use of PROs and their measures, and quantify the effects of lifestyle interventions in patients with SMI on these PROs. Methods Five electronic databases were searched (PubMed/Medline, Embase, PsycINFO, CINAHL, and Web of Science) from inception until 12 November 2020 (PROSPERO: CRD42020212135). Randomised controlled trials (RCTs) evaluating the efficacy of lifestyle interventions focusing on healthy diet, physical activity, or both for patients with SMI were included. Outcomes of interest were PROs. Results A total of 11.267 unique records were identified from the database search, 66 full-text articles were assessed, and 36 RCTs were included, of which 21 were suitable for meta-analyses. In total, 5.907 participants were included across studies. Lifestyle interventions had no significant effect on quality of life (g = 0.13; 95% CI = − 0.02 to 0.27), with high heterogeneity (I2 = 68.7%). We found a small effect on depression severity (g = 0.30, 95% CI = 0.00 to 0.58, I2 = 65.2%) and a moderate effect on anxiety severity (g = 0.56, 95% CI = 0.16 to 0.95, I2 = 0%). Discussion This meta-analysis quantifies the effects of lifestyle interventions on PROs. Lifestyle interventions have no significant effect on quality of life, yet they could improve mental health outcomes such as depression and anxiety symptoms. Further use of patient-reported outcome measures in lifestyle research is recommended to fully capture the impact of lifestyle interventions.

ImportancePeople with a severe mental illness (SMI) have a life expectancy reduced by 10 to 20 years compared with the general population, primarily attributable to cardiometabolic disorders. Lifestyle interventions for people with SMI can improve health and reduce cardiometabolic risk.ObjectiveTo evaluate the effectiveness of a group-based lifestyle intervention among people with SMI in outpatient treatment settings compared with treatment as usual (TAU).Design, Setting, and ParticipantsThe Severe Mental Illness Lifestyle Evaluation (SMILE) study is a pragmatic cluster randomized clinical trial performed in 8 mental health care centers with 21 flexible assertive community treatment teams in the Netherlands. Inclusion criteria were SMI, age of 18 years or older, and body mass index (calculated as weight in kilograms divided by height in meters squared) of 27 or greater. Data were collected from January 2018 to February 2020, and data were analyzed from September 2020 to February 2023.InterventionsWeekly 2-hour group sessions for 6 months followed by monthly 2-hour group sessions for another 6 months, delivered by trained mental health care workers. The intervention targeted overall lifestyle changes, emphasizing establishing a healthy diet and promoting physical activity. TAU (control) did not include structured interventions or advice on lifestyle.Main Outcomes and MeasuresCrude and adjusted linear mixed models and multivariable logistic regression analyses were performed. The main outcome was body weight change. Secondary outcomes included changes in body mass index, blood pressure, lipid profiles, fasting glucose level, quality of life, self-management ability, and lifestyle behaviors (physical activity and health, mental health, nutrition, and sleep).ResultsThe study population included 11 lifestyle intervention teams (126 participants) and 10 TAU teams (98 participants). Of 224 included patients, 137 (61.2%) were female, and the mean (SD) age was 47.6 (11.1) years. From baseline to 12 months, participants in the lifestyle intervention group lost 3.3 kg (95% CI, −6.2 to −0.4) more than those in the control group. In the lifestyle intervention group, people with high attendance rates lost more weight than participants with medium and low rates (mean [SD] weight loss: high, −4.9 [8.1] kg; medium, −0.2 [7.8] kg; low, 0.8 [8.3] kg). Only small or no changes were found for secondary outcomes.Conclusions and RelevanceIn this trial, the lifestyle intervention significantly reduced weight from baseline to 12 months in overweight and obese adults with SMI. Tailoring lifestyle interventions and increasing attendance rates might be beneficial for people with SMI.Trial RegistrationNetherlands Trial Register Identifier: NTR6837