Background: The relationship between psychiatric disorders and musculoskeletal injuries is interesting but has not been investigated in depth.
Study design: A retrospective cohort study, based on a large-sample nationwide database, was performed during 2000-2005 in Taiwan.
Methods: All subjects matching the inclusion criteria of psychiatric-associated ICD9-CM diagnostic codes in 2000 were selected as the inception cohort population. Another cohort-based case-control study was designed, and one sex-matched and age-matched (1:1) control group randomly selected from the population without any prevalent psychiatric disorder in 2000 and incident psychiatric disorder in 2001-2005 was used for comparison.
Results: 64,662 Taiwanese people with any prevalent psychiatric disorder were enrolled in this study in 2000. The 6-year cumulative incidences of orthopedic injuries were 13.61/10,000 for femoral neck/femur fracture and 4.64/10,000, 3.40/10,000, 3.25/10,000, and 3.09/10,000 for radius/ulna or hand fracture, tibia/fibula or patella fracture, ankle or foot fracture, and humeral fracture, respectively. Compared with the control group, this Taiwanese population with prevalent psychiatric disorders had fewer incidences of all orthopedic injuries during the 6 years since 2000, and their cumulative incidence ratios ranged from 0.04 to 0.4 for the different injury sites. For lower-limb fractures, compared with the age stratum of less than 20-years-old, the odds ratios (OR) for the age strata 80-years-old or more and 60-79-years-old were 15.84 (95 % CI 4.55-55.20) and 6.11 (95 % CI 1.92-19.49), respectively. The people with organic psychotic conditions had a significantly greater tendency to suffer upper-limb and lower-limb fractures than those with other psychiatric diagnoses (the ranges of ORs were 3.23-16.67 and 2.13-25.00, respectively).
Conclusion: Subjects with prevalent psychiatric disorders had fewer occurrences of orthopedic injuries than the general population. Among this specific population, an organic psychotic condition and old age were risk factors for suffering fracture of a limb.