The homogeneity and under-representativeness of our sample undermined the reliability and generalization of the findings.
Our intensive efforts to fix appointments during the holiday periods increased moderately their participation, but could not surmount their under-representativeness in the sample.
Researchers should take cognisance of under-representativeness of land-line telephone surveys, of the increasing difficulties in contacting the public and of mounting personnel costs.
Under-representativeness of AUD cases at the ED is unlikely as the generally held view that heavy alcohol consumers are frequent users of medical services and the accident and EDs is supported by a detailed study.
Controlling for any differences in age, sex and education distribution between populations and doing sensitivity analyses to allow for under-representativeness of certain demographic groups made very little difference to the results.
Of these, only the Canadian study has used a multi-language strategy in an attempt to address the under-representativeness of immigrant women in population studies, and the Australian research involved a companion study of three immigrant groups [ 28- 31] in tandem with one of the three population surveys [ 4- 8] undertaken there.
24 The regional differences in the choice of software impact on the geographical representativeness of CPRD; Yorkshire, Humberside, and North East England are under-represented.
Another limitation is the representativeness of the sample: HCPs, specifically MDs, were over-represented while CBO stakeholders were under-represented.
The most important limitations were related to the sample representativeness, since women who had difficulty with the written language and non-Spanish speakers (the questionnaire was written, self-completion, and in Spanish) and women who practise prostitution in the street (it is known that they rarely go to the STD clinics) might be under-represented.
There was a low response rate to the survey and the possibility of non-representativeness as the people who were surveyed had put themselves forward for the research, and men and those from ethnic minorities were under-represented.
First, self-reported data, such as those used by Nakamura et al., are particularly prone to biases relating to representativeness and under-reporting 25, 26.
