The Sample

The survey was carried out in two weeks, one in September 1943 and one in March 1944. These two periods were chosen in order to include in the survey one week with plenty of vegetables in season and one week in which vegetables were both scarce and expensive. 600 children were chosen at random from the list of children who took part in the Vitamin C. test conducted by the Ministry of Health. A letter was sent by the Ministry of Health to each mother, explaining the purpose of the inquiry and asking for her co-operation.

In a later survey among nursing mothers, no such preliminary letter was written and the reception of the investigator was equally favourable. The investigator visited each home, explained the survey, and sought co-operation.

In the first (September) enquiry, altogether 29% of the original sample could not be contacted, refused co-operation, or did not finish the week’s recording.

In the second enquiry, in March, the investigator attempted to visit all those Informants who had taken part in the first enquiry. This aim could not be completely achieved, since 9 families had removed from the district, and 45 families could not be contacted, due to an outbreak of influenza among the investigators, reducing the working time available for this survey, thus 54 (13%) of the Informants of the first survey were not contacted at all in the second. Further, of those approached, 83 or 22% refused to undertake the survey a second time.

Analyses by sex and expenditure group were made of the group of 83 children whose mothers refused to co-operate. It was found that the proportions in different categories did not differ significantly from the corresponding proportions in the contacted sample.

An analysis made by age-groups, however, showed a significant difference. However, this was not great enough to appreciably affect the results.

Refusals show a high proportion of women with children aged under 6 and a low proportion with children aged 12 and 13, but even this difference is not great enough to alter radically the distribution of the sample of those who took part.

The reasons given by those mothers who refused co-operation in the experiment were similar in both enquiries. About half of the mothers who refused did so on grounds of their own ill-health or the ill-health of somebody in family. About one-third of the mothers who refused were unable to keep the dietary record, since they were out to work all day. About 10% said they had so much housework that they could not undertake additional duties. In the second enquiry, only 4 definite objections were raised to the survey. A number of mothers could not give any formulated reason for their refusal.