What did Cooper et al. (2010) find?

Key numbers

What question the review asked

This systematic review asked how four objective measures of physical capability relate to mortality in community-dwelling populations: grip strength, walking speed, chair rising, and how long people could hold a standing balance.

It included observational studies of community-dwelling people of any age, published by May 2009 and found through Embase (from 1980), Medline (from 1950) and reference lists, plus unpublished results from study investigators. Results were pooled with random effects meta-analysis, and the differences between studies were examined.

What it found

Although results varied between studies, there was consistent evidence of an association between each of the four measures and mortality. People who performed less well had a higher risk of death from any cause.

For grip strength, comparing the weakest with the strongest quarter gave a summary hazard ratio for all-cause mortality of 1.67 (95 percent confidence interval 1.45 to 1.93), adjusted for age, sex and body size. That analysis included 14 studies with 53,476 participants, and the studies differed a lot from each other (I2 equals 84.0 percent).

For walking speed, comparing the slowest with the fastest quarter gave a summary hazard ratio of 2.87 (95 percent confidence interval 2.22 to 3.72) after similar adjustments, from five studies with 14,692 participants. Those studies agreed more closely (I2 equals 25.2 percent).

For chair rising, across five studies (28,036 people), the slowest versus fastest quarter had an adjusted mortality hazard ratio of 1.96 (95% CI 1.56 to 2.45), with high heterogeneity between studies (I² 81.9%). This is chair rise on its own, not the composite Short Physical Performance Battery.

Standing balance had not been measured and grouped in comparable ways across studies, so the review did not pool it into one effect. Neither the chair-rise nor the balance results validate Systematic's floor-based Sitting-Rising Test or its eyes-closed Single-Leg Balance test.

Who was studied, and what it does not show

In this review, the walking speed, chair rising and standing balance studies were all in older populations with an average age over 70, which limits how far those results reach. The grip strength association was also found in younger populations, with five studies having an average age under 60 years.

The authors describe these measures as predictors of mortality in older community-dwelling people, not proven causes. The review supports physical capability as something linked to health in groups of people. It does not validate the Systematic assessment or give a clinical cutoff for any of its tests.

The evidence

Each cited source is labeled according to how it supports the particular claim on this page. Direct test evidence, underlying-capacity findings and population reference values are distinguished from Systematic-defined protocols and standards. Historical development notes are retained internally rather than presented as public evidence. A study of an underlying capacity is never presented as validation of the Systematic test itself.

• Underlying-capacity evidence New source

  Cooper et al. (2010). Objectively measured physical capability levels and mortality: systematic review and meta-analysis. BMJ (Clinical research ed.).

  What it found. Lower grip strength, slower walking speed, poorer chair rising and poorer standing balance were each associated with higher all-cause mortality; the slowest versus fastest quarter of walking speed had a summary hazard ratio of 2.87, and the weakest versus strongest quarter of grip 1.67.

  What it does not show. It does not show cause, it does not validate the Systematic assessment, and it does not set Systematic standards.

  PubMed 20829298