Evaluation of sphygmanometers used by family physicians in non-hospital settings in the Bas-Saint-Laurent region

OBJECTIVE To assess the precision and integrity of all aneroid and mercury sphygmomanometers regularly used by family physicians practising outside ho spitals. DESIGN Cross-sectional study. SETTING Private medical clinics and local community health centres in Bas-S aint-Laurent, Qui. PARTICIPANTS A total of 151 of the 166 physicians in this administrative re gion. MAIN OUTCOME MEASURES Precision of the mercury sphygmomanometers was measur ed using the difference between a reading in the absence of pressure and le vel 0. Precision of the aneroid sphygmomanometers was measured using variat ions at pressures of 140 mm Hg and 90 mm Hg compared with those on a calibr ated mercury sphygmomanometer. Integrity of sphygmomanometers, arm cuffs, a nd inflating bulbs was also assessed. RESULTS In all, 258 sphygmomanometers met the inclusion criteria (111 mercu ry sphygmomanometers and 147 aneroid sphygmomanometers). Discrepancies of g reater than or equal to4 mm Hg were found in 15.5% of these instruments (12 .6% and 17.7% of the mercury and aneroid sphygmomanometers, respectively). In 31.0% of the instruments (52.3% and 15.0% of the mercury and aneroid sph ygmomanometers, respectively), one component was malfunctioning. CONCLUSION Sphygmomanometers that measure patients' blood pressure inaccura tely could result in an incorrect diagnosis of hypertension or in a normal blood pressure reading in a hypertensive patient.