A case-control study of rheumatoid arthritis in Lebanon.

A case-control study was conducted to investigate the risk factors contributing to the development of rheumatoid arthritis (RA) in Lebanon. One hundred cases of classical and definite RA were identified from various care facilities in Beirut. Each case was matched with another patient of the same age and sex and free from any arthritic problem. Data on demographic, socioeconomic, genetic and psychosocial factors were collected. Histories obtained from both case and control groups showed a significant difference as to their family history of RA (odds ratio = 2), their past history of trauma (OR = 4) and their history of tonsillitis (OR = 2.2). A significantly higher proportion of cases reported the occurrence of major life events prior to the onset of their disease (OR = 2.5). The perception of the nuclear family environment was compared in both case and control groups. More RA patients were brought up in a family of high conflict (OR = 5), low cohesion (OR = 2) and low expressiveness (OR = 3.5).