Poliomyelitis : a survey of the outbreak in Scotland in 1947.

Date:
1950
Catalogue details

Licence: Public Domain Mark

Credit: Poliomyelitis : a survey of the outbreak in Scotland in 1947. Source: Wellcome Collection.

    17/84 (page 15)
    9. HOUSING—NUMBER OF OCCUPANTS (a) General. This classification of the data was the second to show obvious gaps in the data. In 92 case summaries (4-6 per cent. of the total) the number of occupants in the household of the patient was unstated, generally without any special reason given for the omission. In the tabulation of the data (Tables 13 and 13a) some columns have been combined because of small absolute numbers : for instance, houses with one occupant have not been shown separately from these with two occupants. (6) Number of occupants and type of illness. Distributions are given in the last line of Table 13a. Poliomyelitis, with or without paralysis, had a peak in houses of four occupants whereas patients with a final diagnosis “ not polio- myelitis ” had a more even distribution which lacked a peak at four-occupant houses. Comparisons of these crude distributions which, of course, were at “all ages’ and therefore uncorrected for known differences in age constitutions of the illness types, showed that (a) there was a significant difference between the distributions of poliomyelitis without paralysis and poliomyelitis with paralysis ; (6) there was highly significant difference between the distributions of polio- myelitis with paralysis and “ not poliomyelitis” ; and (c) there was no significant difference between the distributions of poliomyelitis without paralysis and “ not poliomyelitis.” These crude comparisons have given a result totally different from the similar comparisons of apartment distributions, and have indicated roughly that, from the point of view of number of cccupants in a household, poliomyelitis with paralysis was a different disease from the other two main types of illness under consideration, but that these two latter types were not readily distinguishable one from the other, by this criterion. The comparison will be elaborated in the next subsection ; for the moment, it would appear that polio- myelitis with paralysis again tended to be a disease of the better housed—if by better housed is meant a population that is living yenerally with fewer persons per dwelling. The same did not apply to poliomyelitis without paralysis. Deficiencies in information were concentrated in the “ not poliomyelitis ” group, of which 12-6 per cent. had the number of occupants of the household unstated, as against 0-94 per cent. of poliomyelitis cases. (c) Number of occupants, type of illness and age groups. Table 13a gives part of the data of Table 13, arranged as percentages. None of the illness types was homogeneous within itself. In general, with advancing age the patients tended to live in houses with smaller numbers of occupants, a shift mainly due to increases in cases in houses with less than four occupants, with compensating reductions in cases in houses with six (or more) occupants. This trend having shown itself very significantly in the “ not poliomyelitis ” type of illness, as well as in the other two types, it was of interest to make age-specific comparisons. Some comparisons of poliomyelitis without paralysis and poliomyelitis with paralysis revealed a very significant difference at ages 5-9, but only insignificant differences in other age groups. The one significant difference mentioned was enough to bring the difference over the whole age distribution to a point of con- siderable significance, and may be therefore slightly expanded : it was attributable to a relative deficiency of non-paralytic cases in houses with small numbers of occupants (four or less) and a relative excess of such cases in houses with seven or eight occupants. The observed difference has made it impossible to justify the adding together of all cases of poliomyelitis for a further comparison with “not poliomyelitis,” a procedure which was found possible in section 8 (c) above. The slightly longer procedure has therefore been used of comparing *“ not poliomyelitis ” with poliomyelitis (without paralysis) and separately with polio- myelitis (with paralysis) by age groups. The first of these two comparisons led