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  10th International Workshop
October 10-11, 2019
New York

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Physical Function, Falls, Comorbidity
Predict Death in Middle-Aged With HIV

  10th International Workshop on HIV and Aging, October 10-11, 2019, New York
Mark Mascolini
Simple measures of physical function, falls, and comorbidity predicted death 8 years later in 351 middle-aged-to-older people with HIV infection [1]. Timed 400-meter walk proved the strongest individual mortality predictor, followed by comorbidities calculated by the VACS Index, and the Short Physical Performance Battery.
Compared with the general population, people with HIV have higher rates of frailty and impaired physical function. But how much such impairments in middle-aged people with HIV raise the risk of death remains poorly understood. University of Colorado researchers conducted this study to address that question.
The analysis involved 45- to 65-year-old people in whom antiretroviral therapy had controlled HIV infection for at least 6 months. Everyone had an initial evaluation in 2010-2011, including Fried Frailty Phenotype (composite score and grip strength alone), Short Physical Performance Battery (SPPB; composite and chair rise alone), timed 400-meter walk, comorbidities assed by the Veterans Aging Cohort Study (VACS) Index, and any fall in the previous year. Researchers reviewed medical records in 2018 to determine who died; people without a confirmed date of death were censored at their last follow-up visit.
The researchers calculated hazard ratios to estimate the impact of measured variables on survival. They used time-dependent area under the receiver operating characteristic curve (ROC-AUC) to compare how accurately the various physical function measures predict death. A value of 0.5 indicates random chance or no predictability, while a value of 1.0 indicates perfect predictability.
Of the 351 study participants, 85% were men, 15% women, 19% Hispanic, and 16% black. At the initial visit, age averaged 51.9, all participants had a viral load below 200 copies, and 58% had a CD4 count above 500. Twenty-three people (7%) met full frailty criteria, while 164 (47%) were prefrail. In the previous year, 103 people (29%) had 1 or more falls. While 74 participants (21%) had an SPPB score at or below 10, 33 (9%) had weak grip strength. The group averaged 1.4 meters/second in the 400-meter walk and 0.5 chair rises per second.
During follow-up, 245 people (70%) remained alive, 31 (9%) died, and 75 (21%) had an unknown vital status. Six baseline variables independently predicted death during follow-up:
Raised risk of death
-- Pre-frail or frail vs nonfrail: HR 3.16, confidence interval (CI) 1.36 to 7.35
-- More than 1 fall vs none: HR 2.79, CI 1.38 to 5.65
-- Every 10-unit higher (worse) VACS Index: HR 1.55, CI 1.24 to 1.94
-- Lower (worse) SPPB score (10): HR 1.23, CI 1.07 to 1.41
Lowered risk of death
-- More chair rises per minute: HR 0.96, CI 0.93 to 1.0
-- Faster 400-meter walk pace: HR 0.79, CI 0.71 to 0.88
Among individual predictor variables, the strongest predictor of 8-year mortality was 400-meter walk time (ROC-AUC 0.82), followed by VACS score (ROC-AUC 0.80), SPPB (ROC-AUC 0.70), chair rise (ROC-AUC 0.67), frailty (ROC-AUC 0.63), falls (ROC-AUC 0.61), and grip strength (ROC-AUC 0.49).
Among pairs of predictor variables, the strongest predictors of death in 8 years were VACS score + walk (ROC-AUC 0.87), followed by VACS score + chair rise (ROC-AUC 0.81).
The University of Colorado team proposed that "simple clinical measures may be useful tools to guide clinical decisions by identifying those with higher mortality risk over the subsequent 5-10 years."
1. Abdo M, MaWhinney S, Pelloquin R, Jankowski C, Erlandson K. Frailty, physical function impairment, comorbidity burden, and falls are predictive of mortality among middle-aged adults with HIV. 10th International Workshop on HIV and Aging, October 10-11, 2019, New York. Abstract 19.