A prospective study of the association between orthostatic hypotension and falls: definition matters

Background: falls are a common cause of morbidity and mortality in older people. Orthostatic hypotension (OH) is considered an important risk factor for falls, but longitudinal studies have failed to show a clear association. This disparity may be because conventional methods of measuring blood pressure (BP) changes are too imprecise and/or the diagnostic criteria for OH are inappropriate. Over recent years, beat-to-beat BP monitoring techniques, which enabled accurate measurement of vasodepression, have become widely used and in 2011 the American Academy of Neurology produced revised diagnostic criteria for OH. Objective: to use beat-to-beat monitoring to compare the prevalence of OH using the standard and revised diagnostic criteria and to establish which criteria are most valuable in predicting future falls. Design: two hundred and ninety-seven community-dwelling older people aged ≥65 years underwent assessment. Active stand using digital photoplethysmography was used to record postural change in BP. One hundred participants were asked to complete prospective weekly falls diaries for 12 months. Results: OH, defined according to the revised American Academy of Neurology diagnostic criteria, affected 25% of participants and was an independent predictor of falls (odds ratio 10.299, 95% confidence interval [95% CI]: 1.703-61.43, P = 0.011) and time to first fall (hazard ratio 3.017, 95% CI: 1.291-7.050, P = 0.011). OH, defined according to standard criteria, affected 80% of the population and was not associated with falls. Conclusion: OH, defined according to 2011 criteria, is associated with falls and time to first fall. These findings indicate that beat-to-beat monitoring and the 2011 criteria for OH are valuable in the clinical assessment of older fallers.