Abbreviated care-process quality indicator sets linked with survival and functional status benefit in older adults under ambulatory care

Abstract

Objectives: To identify subsets of ambulatory care (outpatient only) quality indicators (QIs) associated with better survival and physical function outcomes.

Design: Observational cohort study.

Setting: Pooled data from the Assessing Care of Vulnerable Elders (ACOVE)-1 study, which measured quality of care using 140 care-process QIs, and the subsequent ACOVE-2 study, which reduced the QIs to 69 ambulatory care QIs.

Participants: Older adults receiving ambulatory care (N=1,015).

Measurements: To prioritize and reduce the QIs into subsets, an expert panel rated each of 69 ambulatory care QIs for the strength of the link between process and benefit, defined as direct trial evidence on older adults or high expectation of benefit if a trial were conducted in older adults. This resulted in three reduced QI sets, reflecting their intended benefit: 17 QIs for survival (ACOVE Quality for Survival (AQS)-17), five QIs to preserve function (AQF-5), and 16 QIs to improve quality-of-life related to physical health and symptoms (AQQ-16). Whether AQS-17 would predict 3-year survival was first tested in 1,015 pooled ACOVE-1 and ACOVE-2 participants. Second, whether AQF-5 (n=74) and AQQ-16 (n=359) would predict change in the Physical Component Summary (PCS) score of the Medical Outcomes Study 12-item Short-Form Survey at 1 year was tested in the ACOVE-2 cohort. Control variables were age, function-based vulnerability, and comorbidity.

Results: Each 20-percentage-point increment in AQS-17 was associated with survival (hazard ratio (HR)=0.83, P=.01) up to 500 days but not thereafter. AQF-5, but not AQQ-16, predicted 1-year improvement in PCS score (1.13-points per 20%-point increment in AQF-5, P=.02).

Conclusion: Subsets of care processes can be linked with outcomes important to older adults. The AQS-17 and AQF-5 are potential tools for improving ambulatory care of older adults.

Keywords: geriatric; mortality; physical function; quality indicators.

Figure 1. Measure Reduction and Flow of Patient Data

Quality indicator (QI) measure development in the Assessing Care of Vulnerable Elders Study (ACOVE-1) originally included acute and ambulatory care measures, and was later reduced to ambulatory-care only measures in ACOVE-2. Only QIs measured in common to both studies were considered for the survival analysis on the pooled ACOVE-1 and 2 datasets, of which 17 were rated as linked (known or highly likely to be associated) with 3- year survival benefit in older adults. For 5 QIs rated as linked to better function and 16 QIs with health-related quality of life (HRQOL) or physical symptom benefits, we testedcomposite measures of quality on ACOVE-2 patients with available baseline and follow-up interviews using the physical component summary score (PCS) of the Short-Form 12.

Figure 2. Survival among older ambulatory-care patientswith better versus poorer quality of care using the ACOVE-Survival Quality (AQS-17) Score

Adjusted Kaplan-Meier curve up to 500 days, with 1015 participants in pooled ACOVE-1 and 2 samples divided into two groups: high (score > 50%, upper curve) versus low (score ≤ 50%, lower curve) quality. Curves adjusted for co-morbidity, gender, age, ACOVE-1 versus ACOVE-2 study, and function-based risk (the Vulnerable Elders-13 Survey score).