Morbidity of rheumatoid arthritis.

an early stage (Hench, 1949). Hitherto it has not been practicable to establish the incidence of spontaneous arrest with any degree of certainty (Snorrason, 1950). In investigating the morbidity of the lesion, one of our chief difficulties has been to obtain a sufficiently large amount of patient material controlled by the same criteria (preferably by the same examiner) for a long period. Various studies have been published already, but either the groups of patients were not homogeneous (Fletcher, 1947; Steinbrocker, 1942; Metropolitan, 1931), or the authors concentrated on the relationship between rheumatism and occupation without examining the morbidity of the primary rheumatoid arthritis (Edstr0m, 1934; Snorrason, 1951). In the Scandinavian countries, useful figures have been furnished by social institutions such as the Invalidity Court (Gram, 1942; Norgaard, 1946), and the National Health Service and practising physicians (Kalbak, 1947; Edstr0m, 1944; Heidemann, 1932; Schelde-M0ller and Sylvest, 1946; Snorrason, 1951). Gram (1942) published an account of 1,014 cases from the Invalidity Court, among which he found a morbidity of 0-67 per thousand in the whole of Denmark for rheumatoid arthritis and chronic arthritis after rheumatic fever. Of these patients, 866 were said to be suffering from rheumatoid arthritis, and the morbidity for this disease alone (Table I) was then 0 58 per thousand (corrected). Norgaard (1946), covering the patient material of the Invalidity Court for the year 1944 (a total of 1,932 applications for invalidity pension or sick benefit), found a morbidity of 0 30 per thousand (Table I). The Swedish Ministry of Social Affairs (H0jer and others, 1945) gave the number of cases of rheumatoid arthritis notified by all the physicians in Sweden as 16,004. This total included all cases of "chronic peni-arthritis" and some cases of chronic arthritis after rheumatic fever. Thus the morbidity reached the strikingly high level of 2-4 per thousand (Table I).