Cardiovascular medications in primary care: treatment gaps and targeting by absolute risk

To measure the use of three major types of cardiovascular medications (antiplatelet, blood pressure lowering, and cholesterol lowering) in primary care, and their level of targeting to individuals at high absolute risk of a cardiovascular event.

Demographic, risk factor, and prescribing data from the Dunedin Royal New Zealand College of General Practitioners Research Unit database were analysed. The data set consisted of 25,384 individuals, men aged at least 45 years and women at least 55 years, who consulted a doctor in 2000 in a practice which supplied electronic clinical notes. People with congestive heart failure were excluded. Five-year risk of a cardiovascular event was estimated using a history of vascular disease or the Framingham risk equation, and correlated with prescribed medications.

Cardiovascular risk could be estimated for only one-third of the study population due to missing risk factor information. Data were largely unavailable on antiplatelet agents and so lipid lowering and blood pressure lowering medications were used to assess the 'treatment gap'. This combination was prescribed to only 28% of those with documented cardiovascular disease. For the remainder without a history of disease and for whom 5-year absolute risk of cardiovascular disease could be estimated, prescription of combination therapy ranged from 8% in the lowest risk group (<5% 5-year risk) to 14-16% in the other risk categories.

Among this primary care population, more than two-thirds of people with vascular disease were not receiving guideline-recommended medications and there was little evidence of targeting by absolute risk for those without disease. However limited conclusions can be made for the latter group because of lack of documented risk factor information. While these treatment gaps may be less now, for example due to increased access to statins, it is probable that substantial gaps remain.