Health Qual Life Out
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Health Qual Life Out · May 2004
Sample size and power estimation for studies with health related quality of life outcomes: a comparison of four methods using the SF-36.
We describe and compare four different methods for estimating sample size and power, when the primary outcome of the study is a Health Related Quality of Life (HRQoL) measure. These methods are: 1. assuming a Normal distribution and comparing two means; 2. using a non-parametric method; 3. Whitehead's method based on the proportional odds model; 4. the bootstrap. ⋯ Strictly speaking, our results and conclusions only apply to the SF-36 outcome measure. Further empirical work is required to see whether these results hold true for other HRQoL outcomes. However, the SF-36 has many features in common with other HRQoL outcomes: multi-dimensional, ordinal or discrete response categories with upper and lower bounds, and skewed distributions, so therefore, we believe these results and conclusions using the SF-36 will be appropriate for other HRQoL measures.
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Health Qual Life Out · May 2004
Quality of life of 5-10 year breast cancer survivors diagnosed between age 40 and 49.
The purpose of this report is to examine the correlates of quality of life (QOL) of a well-defined group of long-term breast cancer survivors diagnosed between the ages of 40 and 49. ⋯ Our results emphasize that younger long-term survivors of breast cancer have a high QOL across several standardized measures. However, the long-term consequences of adjuvant therapy and the management of long-term breast-related symptoms are two areas that may be important for clinicians and women with breast cancer in understanding and optimizing long-term QOL.