Analysing the concept of diagnostic inertia in hypertension: a cross-sectional study

Aims The aim of this study was to quantify diagnostic inertia (DI) when the physician fails to diagnose hypertension and determine its associated factors. Methods This cross-sectional, observational study involved all patients without a diagnosis of hypertension who had their blood pressure (BP) measured at least three times during the second half of 2010 (N = 48,605). Patients with altered mean BP figures (≥ 140/90 mmHg) were considered to experience DI. Secondary variables: gender, atrial fibrillation, diabetes mellitus, dyslipidemia, cardiovascular disease, age and the physician having attended a cardiovascular training course (ESCARVAL). Associated factors were assessed by multivariate logistic regression analysis. Results Diagnostic inertia was present in 6450 patients (13.3%, 95% CI: 13.0–13.6%). Factors significantly associated with DI were: male gender (OR = 1.46, 95% CI: 1.37–1.55, p < 0.001), atrial fibrillation (OR = 0.73, 95% CI: 0.58–0.92, p = 0.007), the ESCARVAL cardiovascular course (OR = 0.88, 95% CI: 0.81–0.96, p = 0.005), diabetes mellitus (OR = 0.93, 95% CI: 0.87–0.99, p = 0.016), cardiovascular disease (OR = 0.77, 95% CI: 0.67–0.88, p < 0.001) and older age (years) (18–44[RIGHTWARDS ARROW]OR = 1; 45–59[RIGHTWARDS ARROW]OR = 12.45, 95% CI: 11.11–13.94; 60–74[RIGHTWARDS ARROW]OR = 18.11, 95% CI: 16.30–20.12; ≥ 75[RIGHTWARDS ARROW]OR = 20.43, 95% CI: 18.34–22.75; p < 0.001). The multivariate model had an area under the ROC curve of 0.81 (95% CI: 0.80–0.81, p < 0.001). Conclusions This study will help clinical researchers differentiate between the two forms of DI (interpretation of a positive screening test and interpretation of positive diagnostic criteria). The results found here in patients with hypertension suggest that this problem is prevalent, and that a set of associated factors can explain the outcome well (AUC>0.80)