Grip strength, multimorbidity, and disability

The presence of two or more chronic health conditions, also known as multimorbidity, is one of the most prevalent health disorders experienced by adults. Adults with multimorbidity and functional limitations represent clinical and financial challenges to the current health care system. The purpose of this three-paper dissertation is to examine the relationship between grip strength, multimorbidity, and the prediction of disability in adults. Data from the 2008 Health and Retirement Study (HRS), a nationally representative, longitudinal study completed on Americans age 50 years and over, are used for the dissertation. The objective of the first paper is to investigate the relationship between grip strength (measured in kilograms, kg) and chronic disease status. The results of this study indicate that when controlling for age and gender, as the number of chronic diseases increased, grip strength decreases. The findings are statistically significant. Grip strength normative values are computed for the second paper. Grip strength norms are stratified by gender (male, female), age (by decades), and chronic disease status (0, 1, 2, >3). The average grip strength for males ranges from 28.10 kg (80 years and older with three or more chronic diseases) to 46.81 kg (50-59 years with zero chronic diseases). Average right grip strength for females ranges from 16.76 kg (80 years and older with two chronic diseases) to 27.48 kg (50-59 years with zero chronic diseases). The third paper investigates a grip strength cutoff value that can be used to predict upper extremity (UE) or lower extremity (LE) disability in adults with and without multimorbidity. Receiver Operating Characteristic curves are calculated for sample, stratified by gender and chronic disease status. In summary, males without multimorbidity and a grip strength of<41kg and males with multimorbidity and a grip strength of <37 kg are anticipated to develop UE and LE disability. In females without multimorbidity and a grip strength of <25 kg and females with multimorbidity and a grip strength of <23 kg are anticipated to develop UE and LE disability.