Reducing delay in patients with Acute Coronary Syndrome and other time-critical conditions: a systematic review to identify the behaviour change techniques associated with effective interventions

Background: Time to treatment in many conditions, particularly acute coronary syndrome is critical to reducing mortality. Delay between onset of symptoms and treatment remains a worldwide problem. Reducing patient delay has been particularly challenging. Embedding behaviour change techniques (BCTs) within interventions might lead to shorter delay. Objective: To identify which BCTs are associated with reductions in patient delay among people with symptoms or conditions where time to treatment is critical. Methods: Data sources: Cochrane Library, MEDLINE, EMBASE, CINAHL and PsycInfoStudy eligibility criteria: Intervention evaluations (RCTs, controlled clinical trials and cohort studies) involving adults (aged >18yrs) and including an outcome measure of patient delay up to Aug 2016.Study appraisal and synthesis methods: Potential studies were screened using a transparent, replicable process. Study characteristics, outcomes and BCTs were extracted from eligible studies. Results: From 39 studies (200,538 participants), just over half (n=20) reported a significant reduction in delay. 19 BCTs were identified plus 5 additional techniques with a mean of 2 (SD=2.3) BCTs and 2 (SD=0.7) per intervention. No clear pattern between BCTs and effectiveness was found. In studies examining patient delay specifically, 3 of 4 studies that included two or more BCTs in addition to the two most commonly used additional techniques reported a significant reduction in delay. Conclusions: Around half of interventions to reduce prehospital delay with time-critical symptoms report a significant reduction in delay time. It is not clear what differentiates effective from non-effective interventions although in relation to patient delay particularly, additional use of BCTs might be helpful. PROSPERO registration number: CRD42014013106.