US trends in quality-adjusted life expectancy from 1987 to 2008: combining national surveys to more broadly track the health of the nation

Abstract

Objectives: We used data from multiple national health surveys to systematically track the health of the US adult population.

Methods: We estimated trends in quality-adjusted life expectancy (QALE) from 1987 to 2008 by using national mortality data combined with data on symptoms and impairments from the National Medical Expenditure Survey (1987), National Health Interview Survey (1987, 1994-1995, 1996), Medical Expenditure Panel Survey (1992, 1996, 2000-2008), National Nursing Home Survey (1985, 1995, and 1999), and Medicare Current Beneficiary Survey (1992, 1994-2008). We decomposed QALE into changes in life expectancy, impairments, symptoms, and smoking and body mass index.

Results: Years of QALE increased overall and for all demographic groups-men, women, Whites, and Blacks-despite being slowed by increases in obesity and a rising prevalence of some symptoms and impairments. Overall QALE gains were large: 2.4 years at age 25 years and 1.7 years at age 65 years.

Conclusions: Understanding and consistently tracking the drivers of QALE change is central to informed policymaking. Harmonizing data from multiple national surveys is an important step in building this infrastructure.

FIGURE 1—

Trends in quality-adjusted life expectancy at (a) age 25 years and (b) age 65 years: United States, 1987–2008. Note. Dashed lines indicate that data was not available for intervening years. The 95% confidence intervals for overall change are smaller than the width of the line. All trends exclude those of “other” race (not White or Black). Source. National mortality data combined with data on symptoms and impairments from the National Medical Expenditure Survey (1987), National Health Interview Survey (1987, 1994–1995, 1996), Medical Expenditure Panel Survey (1992, 1996, 2000–2008), National Nursing Home Survey (1985, 1995, and 1999), and Medicare Current Beneficiary Survey (1992, 1994–2008).

FIGURE 2—

Factors accounting for changes in quality-adjusted life expectancy from 1987 to 2008 at (a) age 25 years (total improvement = 2.4 y) and (b) age 65 years (total improvement = 1.7 y): United States, 1987–2008. Note. BMI = body mass index (defined as weight in kilograms divided by the square of height in meters); HRQOL = health-related quality of life; LE = life expectancy; QALE = quality-adjusted life expectancy. Each bar shows the contribution of that factor to improved population health, holding constant the other contributors to population health. For example, changes in life expectancy held constant the health-related quality of life and share of people in different weight and smoking categories. Obesity or smoking compared the gap between QALE change when allowing behavioral risk factors to change versus holding them constant. Symptoms and impairments explaining less than 0.02 years of QALE change at age 25 years are not shown in either figure: social activity, walking, lifting, bending, standing, reaching, and dexterity. Source. National mortality data combined with data on symptoms and impairments from the National Medical Expenditure Survey (1987), National Health Interview Survey (1987, 1994–1995, 1996), Medical Expenditure Panel Survey (1992, 1996, 2000–2008), National Nursing Home Survey (1985, 1995, and 1999), and Medicare Current Beneficiary Survey (1992, 1994–2008).