Although it is true that retrospective studies are subject to multiple potential "bias in recruitment, recall, and behavior or exposure trends" (Tingen et al. 2004), careful sampling and questionnaire design and use of appropriate methods of analysis can address most of these issues.
We have attempted to minimise these by the careful design of questionnaires (for example by using relatively recent time-frames for recall, where possible), and rigorously training the interviewers to build a good rapport with the respondents and to encourage respondents to correctly recall responses.
Therefore, on the basis of an extensive literature review, interviews with THC doctors, a careful study of the questionnaire for Chinese urban CHC [ 13, 14], we developed a questionnaire for evaluating job satisfaction of Chinese THC employees.
In addition to data collected via questionnaire, a careful test content analysis was conducted based the interpretive model.
Data quality was assured through careful design of the questionnaire.
The high response rate and the careful completing of the questionnaire (maximum 3% missing values in single items) indicate that radiologists regard the study topic interesting and important.
By careful analysis of the questionnaire data, researchers often are able to pinpoint exposure sources to non-environmental factors (e.g. lifestyle or work), local or individual environmental factors (e.g. indoor air quality, food preferences) or general environmental factors.
The careful design of the questionnaires facilitated responders' coherence, which has been identified as an important issue in avoiding inconsistencies by other AHP studies in healthcare [ 41, 42], especially when responders are patients.
Construct validity is one of the characteristics of a questionnaire that deserves careful consideration.
Whilst estimates of sedentary behavior derived from the 7-Day Activity Diaries may be more accurate than a seven day recall questionnaire because of careful daily accounting of time spent in various activities, they will still be subject to reporting errors and biases.
