Abstract

OBJECTIVES--To examine variations in referral for coronary angiography within Northern Ireland and relate these to local death rates from coronary artery disease (ICD rubrics 410-414). DESIGN--A descriptive retrospective analysis of aggregate hospital activity data for 1979-88 and corresponding mortality rates in the local population. SETTING--Two regional referral hospitals and 26 local district council areas. PATIENTS--5173 patients aged 35-74 years with an underlying diagnosis of ischaemic heart disease, whose records contained complete information on their age, sex, and home address. MAIN MEASURES--Age-standardised angiography rates and corresponding standardised death rates derived from the registrar general's reports. RESULTS--Among the 26 constituent district council areas there was significant heterogeneity in the angiography rates, ranging from 62 to 335/100,000 in men and from 7 to 62/100,000 in women (likelihood ratio statistic 856 and 359 respectively). There was no significant association between these angiography rates and the local death rates from ischaemic heart disease. CONCLUSION--The results suggest a non-uniform threshold for referral for angiography. IMPLICATIONS--Clinicians need to examine the appropriate indications for referral for invasive investigation.