A Patient-based severity measure of chronic lung disease: evaluating functional health and predicting health services use

Health-related quality of life predicts onset of asthma in a longitudinal population study

BACKGROUND

Health-related quality of life (HRQL) has been increasingly used as an outcome measure in asthma, but less is known about the prognostic implication of low health-related quality of life. The purpose of this study was to investigate if a set of quality of life measures could predict onset of asthma.

METHODS

In the baseline study 391 subjects without asthma answered a respiratory questionnaire and the Gothenburg Quality of Life (GQL) instrument in 1990. The GQL questionnaire included two parts: (1) the prevalence of HRQL-related symptoms and (2) well-being scores for physical, mental and social dimensions. The participants were also investigated with spirometry and allergy testing. In 2003, the same respiratory questionnaire that had been used in 1990 was sent. There were 290 responders, of whom 22 subjects had developed asthma.

RESULTS

Participants who had developed asthma by the follow-up had a higher prevalence of sleep disturbances (30% vs. 10%), problems with chest pain (16% vs. 2%), depression (40% vs. 20%) difficulty relaxing (40% vs. 13%) and constipation (25% vs. 2%) at baseline than participants who did not develop asthma (p<0.05). Subjects who developed asthma also scored significantly lower on well-being variables as sleep, energy, mood, patience, memory, appetite, fitness and sense of appreciation outside home. These differences remained after adjusting for age, sex, smoking habits, asthma heredity, socioeconomic groups and building dampness.

CONCLUSION

Participants with low health-related quality of life at baseline were more likely to report having developed asthma 12 years later.

Dissemination of Methods and Results From the Veterans Health Study

The Veterans Health Study (VHS) followed a cohort of patients receiving ambulatory care in the Veterans Affairs healthcare system for up to 5 years. One of the principal aims of this study was to develop a library of methodologies including general and disease-specific health outcome questionnaires for use in monitoring the quality of healthcare and for research purposes. The cornerstone for this work is the Veterans RAND 36 and 12 Item Health Surveys (VR-36 and VR-12), a general measure developed in the VHS for measuring the physical and psychologic well-being of the patient. A comprehensive set of disease-specific assessments has also been developed as part of this study for the purposes of monitoring specific chronic conditions more commonly seen in routine ambulatory care settings. Since 1996, more than 2 million questionnaires have been administered in the VA for quality monitoring purposes, using the VR-36 and VR-12. Research studies that have used these batteries span randomized clinical trials in the VA cooperative studies program and clinical effectiveness research. Health assessments using VHS batteries are being disseminated for widespread use outside the VA. Chief among the assessments used is the VR-12, which has recently been included in the 2006 Health Plan Employer Data and Information Set (HEDIS) as part of the Medicare Health Outcomes Survey for monitoring the Medicare Advantage Program. The methods and batteries developed in the VHS are in the public domain and provide a framework for future patient monitoring using standard measures of health.