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RESPONSE LETTER TO DRS. CAMPBELL AND ROBERTSON

sources for the whole of the large population at risk of falls. A population-based approach to fall prevention requires high coverage, the most effective use of highly trained health professionals, and the most efficient use of limited funding. This does not preclude a comprehensive assessment, multiple-intervention, multiple-outcome strategy, but there does have to be evidence of additional benefit from such an approach, which by virtue of the intensity of the assessment and treatment, will almost certainly require a higher budget and be less cost effective than an effective, single-factor intervention strategy. A systematic review and meta-regression of high-quality fall prevention trials found single-factor interventions to be as effective as multifactorial interventions in preventing falls. These analyses were redone to include trials published to August 2008, and the results are essentially unchanged. Multifactorial strategies reduce the rate of falls by 19% (pooled incidence rate ratio (IRR) 5 0.81, 95% confidence interval (CI) 0.75–0.88) and single interventions by 23% (pooled IRR 5 0.77, 95% CI 5 0.67–0.89). An earlier randomized controlled trial of fall prevention using a twoby-two design found that the effective intervention was more effective when used singly than in combination. There are practical problems with adherence in the widespread introduction of multiple interventions. It is possible that multifactorial interventions may have benefits in addition to fall prevention, but such benefits may not be the sole prerogative of this approach. Strength and balance retraining, which is the most widely investigated, long-term, effective fall prevention measure, has cardiovascular, metabolic, and self-confidence benefits in addition to greater stability. Early cataract removal, another single-intervention strategy, decreases falls and improves vision and independence. We should take note of Voltaire’s advice, ‘‘le mieux est l’ennemi du bien’’ and not let the perfect be the enemy of the good. Certainly introduce a population-based, multiplerisk-assessment, multiple-intervention strategy for the whole at-risk population if you can afford to. If you cannot, do not retreat, but open another, more-affordable, more-achievable, more-focused front. Evidence indicates that your advance will be as great.