2A. Appraising Quantitative and Qualitative Research
Quantitative Study
One source of bias during data collection is the use of self-report data (Polit & Beck 2012). Chivers et al. (2001) obtained data through the SF-36 and Beck depression inventory which required the patients to answer questionnaires. If they failed to give accurate answers, it would have affected the validity of the findings. The study design also allowed patients to receive other clinically appropriate treatments that were beyond the study protocol (Chivers et al. 2001). Additional treatments are confounding variables but their influence on the study outcomes was not estimated in the statistical analysis. This reduces confidence in ...