Of 17252 hypertensive patients aged 17 years and over registered with 28 practices in 2007, 15761 (91.3%) had a valid record for both systolic and diastolic blood pressure. The number of hypertensive patients registered in each practice ranged from 123 to 1274, mean 616. Most patients were white (53.5%), 52% were over 65 years and 56% were female. Thirty-eight percent had at least an additional cardiovascular comorbidity and diabetes (21.3%) was the most frequently associated disease followed by coronary heart disease (11.5%), stroke (7.2%), atrial fibrillation (4.7%), renal failure (4.2%) and heart failure (2.5%). A total of 25.2% (3977) of patients had other comorbidities such as depression (15.0%), chronic obstructive pulmonary disease (COPD) (13.0%) and asthma (10.4%). Only 10% of patients were not prescribed antihypertensive medication (Table ).
Characteristics of hypertensive patients. (Source: Wandsworth 2007)
The QOF target produced a significantly higher percentage of patients classified as a HCP 12536 (79.5 %), 95% confidence interval (CI) 78.9–80.2 than did the NICE target 9568 (60.0%), 95% CI 59.9–61.5 p <0.001. Whereas 26 practices (93%) had more than 70% of patients classified as a HPC by using the QOF target, only 4 practices (14%) had more than 70% of patients classified as a HCP when the NICE target was applied (Figure ). The two targets definitions also produced different distributions of HCP across the categories of patient characteristics (Table ). Using the QOF target, 78.1% of men were classified as HCP and the highest percentage of HCP was in those who were 65 years and over, 82.4%. Conversely, by using the NICE target, this age group had the lowest percentage of HCP (59.4%) and overall 59.4% of men were classified as HCP. Regardless of the targets, a higher percentage of HCPs were found in patients of South Asian origin and in those with cardiovascular comorbidity.
Figure 1 Percentage of hypertensive controlled patients in each general practice. The mean percentage with 95% confidence interval (CI) of hypertensive controlled patients by the QOF and NICE target in each general practice is shown
Distribution of hypertensive controlled patients among age, sex, ethinic origin and drug prescription categories by presence of comorbidity¥
The multiple regression models examined the associations between patient characteristics and the probability of being classified as a HCP (Table ). Regardless of the target, men were less likely to be classified as a HCP. An increase in age of one year was associated with a 1% decrease in the probability of being classified as HCP in the NICE model, but this association was not present in the QOF model. Differences in the probability of being classified as a HCP among ethnic groups were only found in the NICE model in that patients of South Asian and Other Asian origin had a significant higher probability of being classified as HCP in comparison with White patients, OR 1.59 95% CI (1.35–1.897) and 1.32 (1.36–1.68) respectively. By using the QOF target, for those prescribed with antihypertensive drugs, there was a significant variation in the probability of being classified as a HCP compared with those patients prescribed no medication. In both models, having cardiovascular comorbidity significantly increased the probability of being classified as a HCP.
Odds ratio of significant patient characteristics associated with being classified as a hypertensive controlled patient
The regression models revealed that the probability of being classified as a HCP by age group is different for each sex (Interaction effect) (Table ). By using the QOF target, men aged 45–64 years and 65 years and over had significantly higher probability of being classified as HCP compared to those (men and women) aged 17-44 years, OR 1.34 (1.08–.165) and OR 2.15 (1.61–2.87) respectively. Similar findings were found when the NICE target was used. By contrast for women, the probability of being classified as a HCP varied with each target. Women aged between 45 and 64 years and 65 years and over, were more likely to be classified as a HCP, OR 1.26 95% CI (1.01–1.57) and OR 2.15 95% CI (1.61–2.87) respectively, compared to those (men and women) aged between 17-44 years when the QOF target is used. However, using the NICE target, women aged 65 years and over were less likely to be classified as a HCP, OR 0.77 95% CI (0.60–0.99).
Figure also illustrates the variation in the probability of being classified as a HCP between sexes across age strata. In comparison with women aged between 17 and 44 years, men at similar age had lower probability of being classified as HCP regardless of target used. However, the probability of being classified as a HCP increased with age for men in comparison with women using both the QOF and NICE target. Men aged 65 years and over, had higher probability of being classified as a HCP than women at similar age regardless of the target.
Variation in the probability of being classified as a hypertensive controlled patient between male and female by age group