Evaluating the implementation of a multidisciplinary lifestyle intervention for people with severe mental illness in sheltered housing: effectiveness-implementation hybrid randomised controlled trial.

Background: Lifestyle interventions can improve health-related outcomes for people with severe mental illness (SMI), but few studies evaluate this potential in everyday settings. After a successful approach in routine inpatient mental healthcare (MULTI), we sought to replicate this multidisciplinary lifestyle-enhancing support in people with SMI living in sheltered housing (MULTI_sh).

Aims: To evaluate the effectiveness and implementation of MULTI_sh (trial registration: NCT03157557).

Method: In an effectiveness-implementation hybrid cluster-randomised controlled trial, six municipalities with sheltered housing facilities in The Netherlands were randomly assigned to MULTI_sh ( = 3) or treatment as usual (TAU, = 3). After 12 months, we evaluated effects on metabolic health, sedentary behaviour/physical activity (ActiGraph GT3X+), quality of life (EuroQol 5D, WHOQoL-Bref) and psychopathology (Brief Psychiatric Rating Scale Expanded Version) using multiple regression, adjusting for baseline values and municipalities (intention to treat and per protocol). In addition, implementation fidelity and barriers/facilitators were evaluated (Measurement Instrument for Determinants of Innovation).

Results: Of 177 eligible patients, 74 (42%) could be included in the analyses. Health outcomes did not substantially improve with MULTI_sh ( = 45) compared with TAU ( = 29). MULTI_sh was not implemented as intended. Most patients and all healthcare professionals believed that patients' lifestyle should be part of treatment, but implementation was primarily (in)directly hindered by organisational factors (e.g. staff shortages, complexity of participation, lack of time and difficulty getting patients involved).

Conclusions: MULTI_sh was not implemented as intended and no clinical health improvements were found. Organisations are decisive in the success or failure of the implementation of lifestyle interventions for people with SMI. More intensive implementation strategies on this level are warranted in sheltered housing.