Objective: To find the efficacy of two methods of detecting previously unknown hypertension--systematic taking of blood pressure (ST) and the Mobile Unit (MU)--and to evaluate the over-diagnosis of arterial hypertension (AHT) in crossover studies which only use epidemiological criteria (EC).
Design: A descriptive study with population and opportunist strategies. An operative MU team attended commercial and work centres within the chosen area. ST looked for AHT in patients attending Health Centre clinics.
Intervention: EC in screening, in line with WHO guidelines and clinical confirmation (CC) in the Health Centres.
Setting: MU in the catchment areas of Novelda, Carrús and C. Jardin Health areas. ST in the San Miguel de Salinas and C. Jardin Health Centres.
Patients: 1654 people over 19 with the MU and 4138 through ST.
Results: Both methods discovered more hypertension in men (MU p = 0.009 and ST p = 0.000) and in the 20 to 39 age group (MU p = 0.000 and ST p = 0.000). EC led to over-diagnosis (5.8% MU and 6.3% ST); greater in men (6.6% and 6.5%) and +/- 60 years old (8.7% and 7.5%). Positive predictive values obtained were 59.8% with MU and 47.4% with ST.
Conclusions: Both methods are useful ways of identifying people suffering hypertension: both young people and men. But CC is essential in order to make a real diagnosis of AHT. Out of every 10 people detected by using EC, only 5 were confirmed by ST and 6 by MU. This information must be borne in mind when evaluating the the prevalence of AHT in epidemiological studies.