The formula used to estimate the sample size in each subgroup was as follows: N = μ α 2 × π 1 − π δ 2 × deff, with an a error of 5%, an overall influenza vaccination coverage rate of 20%, a permissible error of 0.1 π, and a hypothesis of design effect (deff) of 2. Therefore, a sample size of 12294 questionnaires was calculated to obtain accurate estimates for influenza vaccination coverage rates.
Thirdly, the measurements associated with job satisfaction are limited by the size of the questionnaire (only one part of Stamps and Piermonte's questionnaire were used) because it was designed in order to avoid respondent fatigue.
By reducing the size of the questionnaire we should be able to reduce the number of unanswered questions.
Although the response rate was rather good, the complexity and size of the questionnaire may have influenced it negatively.
On account of the size of the questionnaire, questions concerning four cancers studied (breast, colorectal, prostate and lung cancer) were rotated during the successive telephone interviews.
This may not be scalable for large k due to the resulting size of the questionnaire, and it is possible to remove relationships as summarized in the discussion.
It may not be possible or desirable to use large number of questions for this purpose, as that may substantially increase the size of the questionnaire and lead to poor acceptability and participant compliance.
We also reduced the burden on participants by limiting the size and frequency of questionnaires, so as to encourage enrolment and continued participation.
Because the willingness of patients to cooperate in research is known to decreases with the size and number of questionnaires [ 44, 45], shorter ROM assessments may lead to lower drop-out rates.
A total of 180 questionnaires were distributed, and an appropriate total sample size of 167 valid questionnaires was analysed.
