Abstract: Eight studies met our inclusion criteria: three RCTs and five ITS studies involving a total of 135 general practices/primary care clinics, seven hospitals and one outpatient clinic. The studies were heterogeneous in terms of types of interventions, elective procedures and clinical conditions; this made meta-analysis unfeasible. One ITS study evaluating prioritisation of demand through a system for streamlining elective surgery services reduced the number of semi-urgent participants waiting longer than the recommended time (< 90 days) by 28 participants/mo, while no effects were found for urgent (< 30 days) versus non-urgent participants (< 365 days). Interventions aimed at restructuring the intake assessment/referral process were evaluated in seven studies. Four studies (two RCTs and two ITSs) evaluated open access, or direct booking/referral: One RCT, which showed that open access to laparoscopic sterilisation reduced waiting times, had very high attrition (87%); the other RCT showed that open access to investigative services reduced waiting times (30%) for participants with lower urinary tract syndrome (LUTS) but had no effect on waiting times for participants with microscopic haematuria. In one ITS study, same-day scheduling for paediatric health clinic appointments reduced waiting times (direct reduction of 25.2 days, and thereafter a decrease of 3.03 days per month), while another ITS study showed no effect of a direct booking system on proportions of participants receiving a colposcopy appointment within the recommended time. One RCT and one ITS showed no effect of distant consultancy (instant photography for dermatological conditions and telemedicine for ear nose throat (ENT) conditions) on waiting times; another ITS study showed no effect of a pooled waiting list on the number of participants waiting for uncomplicated spinal surgery. Overall quality of the evidence for all outcomes, assessed using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) tool, ranged from low to very low. We found no studies evaluating interventions to increase capacity or to ration demand. As only a handful of low-quality studies are presently available, we cannot draw any firm conclusions about the effectiveness of the evaluated interventions in reducing waiting times. However, interventions involving the provision of more accessible services (open access or direct booking/referral) show some promise.

Plain-language summary: We reviewed the evidence on the effects of interventions in reducing waiting times. We found eight eligible studies (three randomised controlled trials and five interrupted time series studies) involving 135 primary care clinics, seven hospitals and one outpatient clinic. Different interventions, elective procedures and clinical conditions across included studies made pooling of data unfeasible. The quality of the included evidence (to November 2013) ranged from low to very low, as data were obtained from randomised controlled trials that for the most part suffered from serious bias, and from non-randomised studies without a control group. The single study that evaluated an intervention aimed at prioritising demand showed that introducing a system for streamlining elective surgery reduced the number of semi-urgent patients waiting longer than recommended, but did not affect urgent or non-urgent groups. Seven studies evaluated interventions aimed at restructuring the intake assessment/referral process. Three of four studies evaluating effects of open access or direct booking/referral showed beneficial effects: One study showed reduced waiting times for open access to sterilisation through keyhole surgery; another showed that open access to investigative services may lead to reduced waiting times for patients with urinary symptoms (but not for patients with microscopic blood in urine); and one study reported that same-day scheduling reduced waiting times for those seeking child health outpatient services. One study showed no effect of a direct booking system on the proportion of patients reported to have moderate or severe cell changes on the neck of the womb who received an appointment for further investigation within four weeks. Two studies of distant consultancy (instant photography for skin conditions and telemedicine for ear, nose and throat conditions) showed no effect on waiting times to see a specialist. One study reported that using a pooled waiting list did not change the number of patients waiting for routine back surgery within the recommended time. We found no studies evaluating interventions aimed at increasing capacity or rationing demand. As only a handful of low-quality studies are presently available, we cannot draw any firm conclusions about the effectiveness of the evaluated interventions in reducing waiting times. However, interventions involving the provision of more accessible services (open access or direct booking/referral) show some promise.