Use of a treatment algorithm did not improve blood pressure control in primary care patients with type 2 diabetes
Q Does a treatment algorithm improve blood pressure (BP) control in primary care patients with type 2 diabetes?
cluster randomised controlled trial (RCT).
blinded (data analysts).
42 general practices in Nottingham, UK.
1534 patients 18–80 years of age (mean age 64 y, 59% men) who had type 2 diabetes and had not required insulin within 12 months of diagnosis. Exclusion criteria were life expectancy <1 year and inability to attend appointments.
20 practices (797 patients) were allocated to use of a treatment algorithm for 1 year. Practice nurses received training and guidelines on the use of the algorithm for measuring, monitoring, and treating hypertension (ie, monthly BP checks and use of specified antihypertensive drugs [AHDs] for BP ⩾140/90 mm Hg until a target BP <140/80 mm Hg was obtained). 22 practices (737 patients) were allocated to usual care.
proportion of patients who achieved target BP (<140/80 mm Hg if taking AHDs or <140/90 mm Hg if not taking AHDs). Secondary outcomes included proportion of patients prescribed AHDs, proportion of patients prescribed >50% of maximum dose of AHDs, number of AHDs prescribed, mean BP, and rate of BP consultations. Post hoc calculations showed that the study had 82% power to detect an absolute difference of 11% in the percentage of patients in the algorithm group achieving target BP at 1 year.
outcome data were available for all 42 practices (100%) and 93% of patients (intention-to-treat analysis).
At 1 year, the algorithm and usual care groups did not differ for patients reaching target BP (table), patients prescribed AHDs (table), mean BP (table), or median number of AHDs prescribed (1 v 1, rate ratio 1.07, 95% CI 0.91 to 1.26). More patients in the algorithm group were prescribed >50% of the maximum dose of AHDs (table). As well, the algorithm group had a higher rate of BP consultations (4.9 v 3.7 per person/y, rate ratio 1.50, CI 1.25 to 1.80).
Use of a treatment algorithm did not differ from usual care for blood pressure control in primary care patients with type 2 diabetes.
- Christine Opsteen, RN, MN, CDE
Hypertension is an independent risk factor for developing complications in diabetes.1 The cluster RCT by Bebb et al examined the feasibility of a hypertension treatment algorithm in achieving better control in patients with type 2 diabetes. Primary care practices were randomised to usual care or to use of a treatment algorithm by advance practice nurses and general practitioners (GPs) to achieve a target BP <140/80 mm Hg. The algorithm was based on guidelines that used a stepped approach to maximise AHD dose before adding other AHDs. It does not reflect current diabetes guidelines, which target a BP ⩽130/80 mm Hg and recommend a combination of submaximal doses of multiple AHDs to treat the multifactorial pathogenesis of hypertension.2
The algorithm and usual care groups did not differ in the proportion of patients with BP <140/80 mm Hg. Bebb et al concluded that studies on hypertension management in secondary care might not translate to primary care. The results may have been influenced by several factors. Only nurses were trained on the algorithm, but care was provided in collaboration with GPs or by GPs alone. Mean baseline BP was relatively low (146/80 mm Hg), thereby decreasing the potential to show a difference between groups. Patient education was limited, even though patient acceptance and adherence are essential to achieve control.3
The study by Bebb et al reinforces the challenges of aggressive BP management, the need for evidence-based treatment algorithms to guide practice, and the use of advance practice nurses to address the complex needs of managing diabetes and its associated comorbidities.
For correspondence: Dr C Bebb, Renal Unit, Nottingham University Hospitals, Nottingham, UK.
Source of funding: NHS Executive, Trent, UK.