Timing of patient satisfaction assessment: effect on questionnaire acceptability, completeness of data, reliability and variability of scores.

The present study compared the performance of a multidimensional patient satisfaction questionnaire according to the timing of questionnaire administration. Comparisons were made in terms of: (a) the completeness and representativeness of the data set (number of missing questionnaires, number missing item responses, respondents' representativeness to the target population); (b) the questionnaire acceptability to respondents (time and difficulty to complete); (c) the questionnaire reliability; and (d) variability of scores. One hundred and ten consecutive breast cancer patients hospitalised for surgery were randomised between being sent the comprehensive assessment of satisfaction with care (CASC) at 2 weeks (T(2W)) or at 3 months (T(3M)) after hospital discharge. The time to complete the CASC was shorter at T(3M) than at T(2W) and the mean percentage of item omission was lower at T(3M) (1.68) than at T(2W) (3.82). However, the response rate was much higher at T(2W) (87%) than at T(3M) (66%), making item omission non-significant. At both times of questionnaire administration samples were equally biased towards patients having undergone a less invasive surgery. Moreover, the multi-item scales of the CASC demonstrated adequate internal consistency coefficients, except the general satisfaction scale at T(3M), and fairly symmetrical distribution of scores. Response rate should be considered in priority. This criteria favoured an administration of the CASC shortly after discharge. Besides in a cancer patient population care experience and perception may vary in a 6 weeks time lapse. The timing of assessment needs to be clearly specified in cancer patients satisfaction survey.