Development and validation of a prediction model for self-reported mobility decline in community-dwelling older adults

• Published in: Journal of clinical epidemiology Vol. 152; pp. 70 - 79
• Main Authors: Sanchez-Santos, Maria T., Williamson, Esther, Nicolson, Philippa J.A., Bruce, Julie, Collins, Gary S., Mallen, Christian D., Griffiths, Frances, Garret, Angela, Morris, Alana, Slark, Mandy, Lamb, Sarah E., Conway, Oliver, Darton, Francis, Dutton, Susan, Garrett, Angela, Hagan, Daryl, Haywood, Damian, Hewitt, Aimi, Lamb, Sarah, Marian, Ioana, Nevay, Laura, Nicolson, Philippa, Sanchez-Santos, Maria Teresa, Vadher, Karan, Ward, Lesley, Watson, Marion, Arden, Nigel, Barker, Karen, Collins, Gary, Fairbank, Jeremy, Fitch, Judith, French, David, Hanson, Zara, Hutchinson, Charles, Mallen, Christian, Petrou, Stavros
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-12-2022; Elsevier Limited
• Subjects: Adults; Aged; Aging; Calibration; Cohort analysis; Datasets; Decision analysis; Elderly; England - epidemiology; Epidemiology; General population; Humans; Impaired mobility; Independent Living; Logistic Models; Medical prognosis; Missing data; Mobility; Model performance; Older people; Optimism; Prediction model; Prediction models; Primary care; Prognostic; Prospective Studies; Questionnaires; Self Report; Statistical analysis; Variables; England; United Kingdom > UK; Impaired mobility; Model performance; Prediction model; Aging; General population; Elderly; Prognostic
• ISSN: 0895-4356; 1878-5921
• DOI: 10.1016/j.jclinepi.2022.09.002

The aim of this study is to develop and validate two models to predict 2-year risk of self-reported mobility decline among community-dwelling older adults.
We used data from a prospective cohort study of people aged 65 years and over in England. Mobility status was assessed using the EQ-5D-5L mobility question. The models were based on the outcome: Model 1, any mobility decline at 2 years; Model 2, new onset of persistent mobility problems over 2 years. Least absolute shrinkage and selection operator logistic regression was used to select predictors. Model performance was assessed using C-statistics, calibration plot, Brier scores, and decision curve analyses. Models were internally validated using bootstrapping.
Over 18% of participants who could walk reported mobility decline at year 2 (Model 1), and 7.1% with no mobility problems at baseline, reported new onset of mobility problems after 2 years (Model 2). Thirteen and 6 out of 31 variables were selected as predictors in Models 1 and 2, respectively. Models 1 and 2 had a C-statistic of 0.740 and 0.765 (optimism < 0.013), and Brier score = 0.136 and 0.069, respectively.
Two prediction models for mobility decline were developed and internally validated. They are based on self-reported variables and could serve as simple assessments in primary care after external validation.
•First, mobility decline prediction model in older men and women living in the community.•Model performed well in terms of discrimination and showed greater net benefit compared than not using a model.•The simple scoring systems developed are easy-to-use and could be used during a routine clinical consultation.•Predictors with the strongest prognostic power are modifiable (eg, walking ability and balance).