Are they half as strong as they used to be? An experiment testing whether age-related social comparisons impair older people's hand grip strength and persistence

Abstract

Objective

To assess how age-related social comparisons, which are likely to arise inadvertently or deliberately during assessments, may affect older people's performance on tests that are used to assess their needs and capability.

Design

The study randomly assigned participants to a comparison with younger people or a no comparison condition and assessed hand grip strength and persistence. Gender, education, type of residence, arthritis and age were also recorded.

Setting

Age UK centres and senior's lunches in the South of England.

Participants

An opportunity sample of 56 adults, with a mean age of 82.25 years.

Main outcomes measures

Hand grip strength measured using a manual hand dynamometer and persistence of grip measured using a stopwatch.

Results

Comparison caused significantly worse performance measured by both strength (comparison =6.85 kg, 95% CI 4.19 kg to 9.5 kg, control group =11.07 kg, 95% CI 8.47 kg to 13.68 kg, OR =0.51, p=0.027) and persistence (comparison =8.36 s, 95% CI 5.44 s to 11.29 s; control group =12.57 s, 95% CI 9.7 s to 15.45 s, OR =0.49, p=0.045). These effects remained significant after accounting for differences in arthritis, gender, education and adjusting for population age norms.

Conclusions

Due to the potential for age comparisons and negative stereotype activation during assessment of older people, such assessments may underestimate physical capability by up to 50%. Because age comparisons are endemic, this means that assessment tests may sometimes seriously underestimate older people's capacity and prognosis, which has implications for the way healthcare professionals treat them in terms of autonomy and dependency.

Article summary

Article focus

• What is the relationship between ageing and physical strength, measured by hand grip?

• Does stereotype threat affect older people's physical capacities?

• Substantial variability in diagnosis of physical strength could be caused by inadvertent invocation of age stereotypes during assessment.

Key messages

• Psychosocial factors may influence how strongly physical effects of ageing manifest themselves.

• Age comparison creates a stereotype threat, which can reduce older people's hand grip strength by up to 50%—as large as the normal range from middle to old age.

• Healthcare professionals should be aware of the potential for age comparison and stereotypes to affect outcomes of assessments of older people.

Strengths and limitations of this study

• Hand grip is an ‘objective measure’ of physical capability among older people. It is predictive of frailty, morbidity, disability and mortality.

• This first experimental test of the impact of age comparison on older people's hand grip strength demonstrates that it is impaired by comparison with younger people.

• This research was conducted in a non-medical setting and involved participants in good health with a small convenience sample. However the effects remain significant even when age, gender, education, degree of arthritis in the hands, type of residence and location of testing are accounted for.

• Further research is needed to evaluate the prevalence of age comparisons in clinical testing settings, and effects on people of different ages.