Measuring the impact of therapy on medication use: data-linkage study.

Background: The psychological therapies service (PTS) in the Northern Health and Social Care Trust, in Northern Ireland, provides therapies to adults with moderate or severe mental health difficulties. Psychometric outcomes data are routinely collected to assess if a patient demonstrates significant improvement in their main presenting problem area following therapy. The wider impact of therapy is not fully measured in the outcomes database as this would be disproportionately burdensome for both patient and therapist. The present study, to our knowledge, is the first to use data linkage to link patient therapy outcomes data with prescriptions data.

Aims: To widen our understanding of patient medication use before and after therapy.

Method: Using Health and Care Number as a unique identifier, the Psychological Therapies Service - Routine Outcome Measurement Database ( = 3625) and data from 72 500 controls were linked with data from the Enhanced Prescribing Database (EPD). The EPD data were sourced from the Honest Broker Service.

Results: Key findings from the study were: (a) the odds of PTS clients using antipsychotics in the year before therapy were 25 times greater compared with controls (odds ratio (OR) = 24.53, 95% CI 20.16-29.84); (b) in the 1st year post discharge, PTS clients who clinically improved post therapy discharge were more likely than 'non-engagers' and 'non-improvers' to come off antianxiety medication (OR = 0.61, 95%, CI 0.38-0.98); and (c) therapy did not have an impact on antidepressant use.

Conclusions: The results highlight the need for discussion between therapy services, GPs and psychiatry about whether more engagement and collaboration is needed to plan phased reduction in medication.