VII COMPARISON WITH EARLIER INQUIRY

In July 1942 the Wartime Social Survey made an inquiry into Diphtheria Immunisation for the Ministry of Health. Unlike the present inquiry this was concerned only with particular areas and no attempt was made to select a nationally representative sample. The areas were chosen by the Ministry of Health and were classified in two groups. (i) “Bad” districts where the proportion of children immunised was thought to be low, and, (ii) “Good” districts where it was thought that a high proportion of children were immunised.

715 parents were interviewed in the “good” areas, and 863 in the “bad” areas.

In the present inquiry the areas visited previously were visited again, among others. It was not possible to make as many interviews in these areas as before since this would have distorted the national sample. The results given in this section are based on 365 interviews made in the “good” areas, and 425 in the “bad” areas. The areas chosen were as follows:-

The method of sampling used in the earlier inquiry was the same as that used in the present inquiry, except that children were selected from the Ministry of Food’s records and not from the National Register.

The questions asked in the two inquiries were not all the same. When the second inquiry was planned the Ministry of Health did not require some of the information obtained in the first inquiry and some additional information was wanted. It is therefore only possible to make comparisons of the results of some of the questions.

In some cases the method of classifying replies to the same questions, was different in the two inquiries. It was found as a result of the earlier inquiry, that a different way of classifying them would be more useful, and it was decided that it was worth sacrificing comparibility for the sake of getting better information.

(1) Incidence of Immunisation

In the first inquiry mothers were asked whether each of their children (aged under 16) had been immunised, and the results for all children, and not only for those selected from the records, were tabulated. The results of the two inquiries were analysed in two age groups as follows:-

It will be seen that there has been a considerable increase in the proportion of children immunised in both types of area. The increase is more considerable in the bad areas than in the good areas, and amongst younger children than amongst older children. By the time of the 1945 inquiry the same proportion of children aged 5 to 15 had been immunised in the bad areas as in the good areas, but the proportion of children aged under 5 who had been immunised is still lower in the bad areas, although it was almost twice as great as in 1942.

In the 1945 inquiry it was found that 68% of all children in the bad areas had been immunised. This is about the same proportion as had been immunised in the country as a whole.

(2) Ages at which Children were Immunised

The ages at which children had been immunised in the two types of area at the different periods, were as follows:-

The proportion of children immunised in their younger years has increased in both types of area, but particularly so in the bad areas.

(3) Was the immunisation completed?

There appears to have been a slight increase in the proportions of immunisations that were completed in the good areas. The difference between the result for the bad areas at the two periods is not statistically significant.

(4) Knowledge about Diphtheria

Answers to the question “Do you know what causes diphtheria?” were classified differently in the two inquiries. It was found in the first inquiry that some mothers said diphtheria was caused by “germs”, but whether or not these mothers know that the germs were passed from one person to another, was not ascertained. It may be that some of them thought the germs came from bad sanitation or other sources. In the present inquiry mothers who gave this answer were asked where the germs came from before their answers were classified.

The results of the second survey suggest that people in both types of area are less well informed as to the cause of diphtheria than might be supposed from the results of the first inquiry, if it was assumed that those saying “germs” or “germs in the throat” knew that diphtheria was an infectious disease. It appears from the second survey that a high proportion of those saying “gems” in the first inquiry did not in fact know where the germs came from.

The higher proportions saying “don’t know” in the second inquiry may be accounted for by the fact that those who first of all said “germs” and then said that they did not know where the germs came from, were included in this group.

It will be noted that mothers living in the bad areas are not less well informed, but know slightly more about the cause of diphtheria than mothers living in the good areas, although the incidence of immunisation was somewhat lower in the bad areas.

In the earlier inquiry a higher proportion of mothers in the bad, than in the good areas, said they did not know. But it is clear from the evidence given by the second inquiry that many of those in the good areas who thought they knew the cause, did not in fact know it correctly, and this would have been shown had they been asked further questions about it.

The first inquiry showed no difference between the proportions mentioning immunisation in the good and bad areas, and the second inquiry does not show any statistically significant difference between the two groups. In both types of area, however, the proportion giving the correct answer is somewhat higher in 1945 than in 1942.

It is not possible to compare precisely the reasons given by mothers in the two inquiries as to why they did not have children immunised owing to a difference in the method of classifying replies. However, consideration of the two sets of results does not suggest that there are any marked changes in the reasons.

Questions about publicity media were asked in different forms in the two inquiries, and it is not possible to make any comparison.