Factors influencing quality of life in breast cancer survivors.

Longitudinal data from 195 breast cancer survivors were used to identify factors affecting the level and rate of change in quality of life after completion of treatment. Women were interviewed up to four times at approximately yearly intervals using Kaplan and Bush's Quality of Well Being instrument (QWB). Random coefficient regression analysis was used to model QWB as a function of time since diagnosis and personal characteristics. QWB scores decreased over time and the rate of decline increased with age (p = 0.032). This was similar to declines in women with benign breast biopsies, but overall QWB levels were lower in women with breast cancer. Having a spouse tended to slow the rate of decline in breast cancer survivors (p = 0.004). The presence of comorbidity was associated with significantly lower QWB levels (p = 0.037) but did not affect the rate of change over time. Education, family history of breast cancer, cancer stage and treatment modalities were not significantly related to QWB levels or rates of change. Breast cancer survivors experience a reduction in quality of life that persists for years after treatment and is similar in magnitude to that associated with other health problems.