Self-reported major mobility disability and mortality among cancer survivors

Abstract

Objective: To quantify the prevalence of self-reported major mobility disability (SR-MMD) and its association with mortality in a nationally-representative sample of cancer survivors.

Materials and methods: This study included patients with a history of cancer who participated in the National Health and Nutrition Examination Survey 19992010. SR-MMD was defined as self-reported difficulty or inability to walk a quarter of a mile. Vital status through December 15, 2011 was ascertained from the United States National Center for Health Statistics. Multivariable-adjusted Cox regression models were used to quantify the hazard ratio (HR) and 95% confidence interval (CI) between SR-MMD and mortality.

Results: The study included 1458 cancer survivors who averaged 67.1 years of age. At baseline, 201 (13.7%) participants had SR-MMD. During a median follow-up of 4.7 years, 434 (29.8%) participants died. SR-MMD was independently associated with a higher risk of all-cause mortality [HR: 2.15 (95% CI: 1.56-2.97); P < 0.001] and cancer-specific mortality [HR: 2.49 (95% CI: 1.53-4.07); P < 0.001]. The association between SR-MMD and all-cause mortality was not modified by age, sex, time since cancer diagnosis, body mass index, or comorbid health conditions.

Conclusion: SR-MMD is an easily ascertainable metric of physical function that is associated with a higher risk of mortality among cancer survivors. Integrating measures of physical function may help to guide clinical decision-making and improve long-term prognostication in this population. Interventions that prevent the development of SR-MDD, such as physical activity, should be evaluated in this population.

Keywords: Ambulation; Patient reported outcome; Physical activity; Physical function; Survival.