Cost effectiveness of dietary interventions for individuals with mental disorders : A scoping review of experimental studies

Aim
This scoping review aimed to explore the extent of the evidence of experimental studies evaluating the cost effectiveness of dietary interventions in individuals with mental disorders.

Methods
Five databases (CINAHL, EMBASE, MEDLINE, PsycINFO and Scopus) were searched to October 2020 for cost-analysis studies of interventions aiming to improve dietary intake in people with mental disorders. No restriction was placed on participant age, mental disorder type or intervention design. Results are presented narratively.

Results
Of 2753 articles identified, 13 articles reporting on eight studies were included. Studies were RCTs (n = 5), cluster RCT (n = 1), cluster preference RCT (n = 1), and pre-post test (n = 1). Seven studies were in community settings (eg, outpatient clinics), and one study in the community housing setting. All studies were in adults, seven included male and female participants, and one included only females. Defined mental disorder diagnoses included serious/severe mental disorders (n = 3), major depression (n = 2), schizophrenia, schizoaffective disorder or first-episode psychosis (n = 1), any mental disorder (n = 1), and bulimia nervosa (n = 1). Five interventions were multi-behaviour, two were diet only and one was eating disorder treatment. Cost analyses included cost-utility (n = 3), cost-effectiveness (n = 1), cost-utility and cost-effectiveness (n = 3), and a costing study (n = 1). Two studies (25%) reported positive results in favour of cost effectiveness, and four studies reported a mix of positive and neutral results.

Conclusions
There is limited evidence evaluating the cost effectiveness of dietary interventions in individuals with mental disorders. Additional studies in various settings are needed to confirm cost effectiveness of different interventions.