What benefit do patients expect from adding second and third antihypertensive drugs?

aimsTo discover whether patients have the same expectations of benefit from taking the first and any additional drugs for the treatment of hypertension and to investigate any patient characteristics which predict willingness to take treatment.

methodsThis was an anonymous questionnaire survey carried out in a single primary care group. A random sample of patients from the practice list stratified by age and gender were surveyed to determine what benefit they required before deciding to receive first and subsequent drugs to treat hypertension. They were asked to indicate the largest number needing treatment for 5 years (NNT5) to prevent myocardial infarction in 1 (smallest benefit) that would persuade them of the need for treatment. Demographic information which might explain variability in enthusiasm for treatment was also collected. RESULTS

participantsrequired far higher benefit to consider drug treatment than expected with a mean NNT5 for the first treatment of 15.0 (95% CI 12.3, 17.8). Marginal benefit demanded for the addition of second and third treatments was at least as great with an NNT5 of 13.2 (95% CI 10.8, 15.7) and NNT5 of 11.0 (95% CI 8.6, 13.4). Additional factors influencing willingness to take treatment were gender with a difference in NNT5 between men and women of 7.1 (95% CI 1.7, 12.5), difficulty in making the decision (very easy vs very difficult) of 14.9 (95% CI 6.0, 23.8), and years in full time education 2.0 (95% CI 0.9, 3.0) for each additional year of education. Any slope of NNT5 with increasing number of tablets disappeared when gender, years in education, and difficulty in reaching a decision were taken into account simultaneously.

conclusionsPeople may have greater expectation of benefit from antihypertensive drug treatment than it provides. They certainly do not view the addition of subsequent drugs as any lesser step than starting the first in terms of the benefit expected. Full understanding of both the risks and benefits may be of critical importance with those spending longer in full time education and those expending more effort in making the decision accepting more treatment. The discrepancy between benefit expected and that available demands further research into methods of determining patients' expectations and informing individual patient decisions.