Service-level interventions to reduce waiting time in outpatient and community health settings may be sustained: a systematic review.

Aim: The primary aim of this systematic review of the literature was to determine whether interventions to reduce waiting time in outpatient and community health services can be sustained. The secondary aim was to describe associations between sustainability and features of waiting time interventions and the settings in which they have been implemented.

Methods: CINAHL, Medline, Embase and Psych Info databases were searched, combining the search concepts 'waiting time or waiting lists', 'outpatient or community care' and 'sustainability'. Studies were included if they tested a service-level intervention that aimed to reduce waiting in an outpatient or community setting and reported data with a minimum 12-month follow-up period. Data were extracted and analysed using a descriptive synthesis. Methodological quality was evaluated using the mixed-methods appraisal tool (MMAT). Waiting interventions were rated as sustained, partially sustained or not sustained using predetermined criteria. The Grading of Recommendation, Assessment, Development and Evaluation was used to describe certainty of evidence for different intervention approaches.

Results: Screening of 7770 studies yielded 22 papers investigating the sustainability of waiting interventions for approximately 150 000 clients. Many were of lesser quality, with 14 not meeting more than 3 of 5 criteria on the MMAT checklist. Intervention types were categorised as referral entry, open access and substitution, used either alone or in combination. There was low certainty evidence that all interventions were associated with sustained reductions in waiting time, often with large effect sizes, but the findings are limited by low methodological quality of many studies and the risk of publication bias.

Conclusion: Reductions in wait times and waiting lists for health services can be achieved and sustained following interventions, but further high-quality research would better inform service providers about what interventions are most effective and provide the greatest return on investment.