Factors Influencing HRQOL

A number of studies have attempted to determine the factors that influence a patient's HRQOL. Many of the findings disagree with each other, possibly because of the many different measurement instruments used. The researchers did find several factors in common: airflow limitation, smoking, age, frequency of exacerbations, and coping strategies.

Airflow limitation: Mahler and colleagues found that FEV1 was a predictor of 5 out of 6 components in the Medical Outcome Study. Other studies using the SGRQ found that changes in HRQOL scores correlated with changes in FEV1. Tsukino et al found that FEV1 can be an influence on the HRQOL scores only with patients having stable COPD. Wegner et al reported that lung function had no impact on HRQOL with patients having severe COPD.

Smoking: Prigatano et al found that patients who continued smoking had a significantly reduced HRQOL. Tsukino et al found that current smoking was not an influence, but lifetime smoking habits had a strong correlation to reduced HRQOL scores.

Age: Tsukino et al found a direct correlation between advanced age and reduced HRQOL scores.

Frequency of exacerbations: In an evaluation of the relation­ship between exacerbation and overall quality of life, Seemungal et al found that exacerbations may have an important impact on health status and quality of life. Health status measures revealed a strong relationship between lowered HRQOL and exacerbation frequency. The study therefore concluded that a reduction in frequency of exacerbations would improve feelings of well-being.

Coping strategies: Too often, patients cope with impairment by avoiding situations that cause trouble and giving up hobbies they enjoy. Patients have coped with increasing dyspnea by avoiding exercise and giving up activities such as gardening, skiing, and daily walks. As the disease progresses, they may rely on help from friends, relatives, or hired help to perform such daily activities as cleaning, washing, and cooking.

Several studies have suggested that a patient's ability to cope with the disease can have an impact on quality of life. Ketelaars and colleagues found that patients who tend to deny their disease experience less limitation in their activities and are less influenced by the negative aspects of their disease in daily life. A negative correlation between 2 statements regarding “emotional reaction” and “well-being” suggest that coping in a highly emotional manner has a negative impact on a general feeling of well-being.

Other possible influencing factors have been suggested, including sex, social class, economic position, and household composition.

In Summary Factors that Influence HRQOL:

• airflow limitation: there is evidence that as airflow limitation increases, HRQOL decreases
• smoking: a previous history of smoking and continued smoking have both been linked to a reduced HRQOL
• age: advanced age has been linked to reduced HRQOL
• studies have shown a direct correlation between frequency of exacerbations and HRQOL
• coping strategies: patients who tend to deny their disease experience less limitation in activities and a higher HRQOL