Individual and Combined Associations of Cognitive and Mobility Limitations on Mortality Risk in Older Adults

Objective

To evaluate the potential independent and combined associations of cognitive and mobility limitations on risk of all-cause mortality in a representative sample of the US older adult population who, at baseline, were free of cardiovascular and cerebrovascular disease.

Patients and Methods

Data from the 1999 to 2002 National Health and Nutrition Examination Survey were used to identify 1852 adults (age, 60-85 years) with and without mobility and/or cognitive limitations. Hazard ratios (HRs) for mortality risk were calculated for 4 mutually exclusive groups: no limitation (group 1 as reference), mobility limitation only (group 2), cognitive limitation only (group 3), both cognitive and mobility limitations (group 4).

Results

Compared with group 1, the adjusted HRs (95% CI) for groups 2, 3, and 4 were 1.72 (1.24-2.38), 2.00 (1.37-2.91), and 2.18 (1.57-3.02), respectively. The mortality risk when comparing group 4 (HR, 2.18) with group 3 (HR, 2.00), however, was not statistically significant (P=.65). Similarly, the mortality risk when comparing group 4 (HR, 2.18) with group 2 (HR, 1.72) was not statistically significant (P=.16).

Conclusion

Although the highest mortality risk occurred in those with both limitations (group 4), this point estimate was not statistically significantly different when compared with those with cognitive or mobility limitations alone.