SUMMARY The prevalence of mild and severe radiological osteoarthritis was investigated in a random sample of 6585 inhabitants of a Dutch village. Radiographs were graded 0-4 according to the criteria described by Kellgren and Lawrence. The prevalence of radiological osteoarthritis increased strongly with age and was highest for cervical spine (peak: men 84.8%, women 84-3%), lumbar spine (peak: 71-9%, women 67.3%), and distal interphalangeal joints of the hands (peak: men 64-4%, women 76%). Prevalence did not exceed 10% in sacroiliac joints, lateral carpometacarpal joints, and tarsometatarsal joints. Severe radiological osteoarthritis (grade 3 or grade 4) was uncommon under age 45; in elderly persons the prevalence of severe radiological osteoarthritis did not exceed 20% except for the cervical and lumbar spine, distal interphalangeal joints of the hands and, in women only, metacarpophalangeal joints, first carpometacarpal joints, first metatarsophalangeal joints, and knees. Overall, differences between men and women were small except for hips and knees; however, severe radiological osteoarthritis was found in a higher proportion in most of the joints in women. Our data were compared with data from similar population surveys. The slope between joint involvement and age was strikingly constant for most of the joints. Differences between populations were mainly differences in level. These differences of prevalence of radiological osteoarthritis may be attributed to interobserver differences-that is, different criteria used to establish radiological osteoarthritis, in addition to genetic or environmental factors, or both.

SUMMARY This report deals with the question of whether or not the established association of HLA-DR4 with rheumatoid arthritis (RA) can also be detected in cases of RA as diagnosed in a population survey. For this purpose 6584 persons older than 19 years living in a single community in The Netherlands were investigated for the presence of rheumatoid arthritis and related abnormalities. After five years 83 patients with RA, 30 with only erosive abnormalities on radiological examination (Rad), and 48 with only rheumatoid factor (RF) were reinvestigated and typed for HLA and allotypes of immunoglobulin G heavy chain (GM). On the classification of the initial survey no significant association of HLA-DR4 or GM could be detected in any of the three categories. When the information of the follow-up investigation was taken into account, a reappraisal of the classification resulted in 53 cases with RA, 18 with Rad only, and 35 with RF only. The frequencies of HLA-DR4 and GM in the three categories were also about the same as those in normal controls. However, an increase in the frequency of HLA-DR4 was observed in cases of RA positive for Rad, RF, or both. We found no evidence for an interaction between HLA-DR4 and GM. Our results suggest that rheumatoid arthritis is a heterogeneous disorder, only a fraction of which is associated with HLA-DR4. At present no single determinant of RA such as Rad or RF can characterise the HLA-DR4-associated, and most probably more severe, type of RA.

The diagnostic value of biphasic radiographic examination of the stomach and duodenum was compared with that of fiberoptic endoscopy in a prospective, blinded study of 385 patients with dyspepsia. This investigation was directed at gastric malignancies and peptic ulcers. Methodologically there is no absolute standard for a study of this kind because histologic examination is useful for detection of cancer but inadequate for ulcers. As an alternative, kappa indexes and the sensitivity and specificity, as derived by Hui and Walter, were calculated and compared. For the detection of gastric carcinoma, radiographic and endoscopic findings had almost perfect agreement beyond chance. For gastric ulcers, radiography and endoscopy had substantial agreement, which became perfect if small ulcers (less than 5 mm) were excluded. For duodenal ulcers, radiography had a lower sensitivity than endoscopy; this disagreement disappeared if small ulcers were excluded. Both methods have equal merit; choice of the initial diagnostic procedure will therefore depend on cost, discomfort to the patient, and risk of complications.

Biphasic radiography was compared with fiberoptic endoscopy in detecting gastric erosions in a prospective, blinded study of 385 patients with dyspepsia. Because no absolute standard was available for the comparison, since histologic confirmation of all erosions was not possible, the kappa statistic was used to compare results from both modalities. Flat (incomplete) erosions were detected with endoscopy only and were considered to be present in 42 patients (11.2%). Varioliform (complete) erosions were identified with both radiography and endoscopy in 12 patients (3.2%). For the detection of varioliform erosions, a substantial agreement beyond chance between both modalities was found (kappa = 0.73; standard error, 0.12). Thus, flat erosions were detected with endoscopy only, whereas state-of-the-art radiography and endoscopy were equally sensitive for detecting varioliform erosions. Histologic confirmation of erosions was obtained in only 75% of the patients. It is unknown whether the demonstration of erosions with radiography and/or endoscopy correlates with dyspepsia.