Although the multifactorial nature of osteoarthritis (OA) is well recognized, genetic factors
have been found to be strong determinants of the disease. Evidence of a genetic influence …

Back pain is among the most common conditions for which patients seek medical care.
Interventions based on behavioral and cognitive principles and exercise programs are …

Objective Twin concordance data for rheumatoid arthritis (RA) on their own provide only
limited insight into the relative genetic and environmental contribution to the disease. We …

The challenge faced by research into the genetic basis of complex disease is to identify
genes of small relative effect against a background of substantial genetic and environmental …

Objective. To determine the relative effects of genetic and environmental factors in
susceptibility to ankylosing spondylitis (AS). Methods. Twins with AS were identified from the …

We report the concordance rate for RA in a nationwide study of 91 monozygotic (MZ) and
112 dizygotic (DZ) pairs. Twin pairs were recruited from both a national media campaign …

Objective. To test the hypothesis that cigarette smoking is associated with susceptibility to
rheumatoid arthritis (RA) by comparing smoking history between twins with RA and their …

Objective Degenerative intervertebral disc disease is common; however, the importance of
genetic factors is unknown. This study sought to determine the extent of genetic influences …

Migraine is a common neurovascular brain disorder that is manifested in recurrent episodes
of disabling headache. The aim of the present study was to compare the prevalence and …

The classic twin study is sometimes described as “the perfect natural experiment” for the
investigation of the aetiology of complex disease, but assumptions of the twin design need to …