Pressure on commissioning budgets has meant commissioning organisations increasingly looking to referral management as a means of helping manage demand. However, evidence about the impact the different approaches to referral management have is weak. In particular, commissioning organisations have struggled to assess the potential for active referral management to reduce demand.
“It was striking how little formal evaluation of their local schemes PCTs had undertaken, and there was a lack of any quantitative assessment of the impact on demand.”
(Referral Management: Lessons for Success, Kings Fund, 2010)
The Strategic Analysis team were asked by a group of CCGs to retrospectively evaluate the effect of a local musculoskeletal Integrated Clinical Assessment and Treatment Service (ICATS) on the level of referrals from primary care to outpatient services. We used an interrupted time series design to assess mean monthly changes in outpatient attendances relative to projected attendances without the ICATS service based on pre-intervention trends. Interrupted time series is a quasi-experimental approach, which attempts to detect whether the intervention has had an effect significantly greater than any underlying trend over time. This type of approach is often used in ‘real world’ situations that do not permit an experimental design (e.g. http://www.bmj.com/content/346/bmj.f403).The basic time series design was strengthened by the inclusion of a number of novel control variables that should not have been affected by the intervention.
We were able to provide commissioners with an estimate of the effect of the new ICATS service on numbers of outpatient attendances, numbers of inpatient admissions and associated changes in costs. The report provided to commissioners also included a significant finding relating to the sorts of inpatient admissions that had reduced the most.