Better by half: hypertension in the elderly and the 'rule of halves': a primary care audit of the clinical computer record as a springboard to improving care.

BACKGROUND: Despite recent studies highlighting the benefits of treating elderly hypertensives, researchers have shown that the taking on board of these findings has been disappointing in primary care, where the 'rule of halves' still applies. Clinical computers could help performance in this area, yet national and local research suggests that they are under-used.
OBJECTIVE: Our aim is to develop a pragmatic intervention which aims to: improve patient care by translating research findings into practice, increase meaningful computer use, establish 'paperless' annual audits and improve 'networking' between practices.
METHOD: Following a baseline audit to ascertain accuracy, the computer records of participating practices were tested against the 'rule of halves' for hypertension. Results were presented to each practice (individual practice and aggregate data for all practices). Management guidelines, standardization of computer recording, achievable targets and review dates were agreed. The study was conducted in West London practices using the EMIS computer system in 1996/1997.
RESULTS: An 81% (22/27) practice response rate was achieved. Baseline audit was completed for 22 practices. Fifteen practices appear to be using their computer regularly (two-thirds). Using strict definitions, 'the rule of halves' still applies. Using looser definitions, three-quarters of hypertensives are known, two-thirds are treated and just under two-thirds are controlled. This project identified wide inter- and intra-practice variation in: use of the computer, patient follow-up, attainment of target BP, rounding BP readings to target levels and prescribing patterns.
CONCLUSION: This focused training intervention has introduced practices to evidence-based proactive care and highlighted an important application for clinical computers. A local network of practices has been established for future projects. For elderly patients registered with a GP, the rule of halves has been improved upon, provided that a figure of 160/90 is taken as an adequate control. Attainment of target BP in treated hypertensives was similar to that reported from large trials. There is enormous scope for improving identification and follow-up of hypertensives using clinical computers and systematic models of care. The wide inter-practice variation in hypertension management requires further study.