Epidemiology of hip fractures in Oslo, Norway
Introduction
Hip fracture represents an important cause of morbidity, mortality, and health care costs in the elderly.4, 5, 16, 20, 24 The incidence of hip fractures in Oslo has shown a secular increase during the past decades.8, 9 In 1988/89, the incidence per 10,000 for the age group ≥50 years was 118.7 in women and 45.4 in men.9 These incidence rates exceeded all those ever reported in Norway and elsewhere. However, recent studies from Malmö32 and Uppsala30 in Sweden and central Finland13 have shown that the incidence of hip fractures is no longer increasing, indicating a trend break.
In general, the incidence of hip fractures is very high in the Scandinavian countries.3, 5, 7, 9, 32 This suggests that the cold climate of these countries may contribute to the high incidence.19, 32 However, several reports have questioned this hypothesis.15, 22 The aim of the present study was to report the current incidence of hip fractures in Oslo to elucidate whether there has been a further increase during the last decade, and to compare this incidence with recent data from other countries. In addition, the seasonal variation in the occurrence of hip fractures and the relation between outdoor temperature and number of hip fractures were studied.
Section snippets
Materials and methods
In Oslo, there are four somatic hospitals to which a patient sustaining a hip fracture is referred for treatment. Three of these hospitals provide emergency service. Using the electronic diagnosis registers of the four hospitals, all patients with the International Classification of Diseases, ninth revision (ICD-9) code 820.X (hip fracture) from May 1, 1996 through April 30, 1997 were identified. In addition, the lists of the operating theater of the three hospitals with emergency service were
Results
A total number of 1335 hip fractures was identified. For nine patients the medical records were not available and the diagnosis was verified by review of X-ray and corresponding reports. Eight patients with cancer metastases at the fracture site and 11 patients not residing in the city of Oslo were excluded. The number of hip fractures included was thus 1316. These fractures occurred in 1291 patients as 25 women sustained two fractures within the inclusion period. Only ten patients were
Discussion
The present study shows that the incidence of hip fractures in Oslo has not changed significantly during the last decade, and it is still among the highest in the world. Furthermore, no significant seasonal variation in the distribution of hip fractures and no correlation between mean outdoor temperature and number of fractures for each month was found for 1996/97, whereas both a seasonal variation and a correlation between temperature and number of fractures were demonstrated for 1978/79.
Acknowledgements
The authors thank the four somatic hospitals of Oslo for help and assistance during the data collection. This study was supported financially by an unrestricted grant from Eli Lilly, Norway.
References (35)
- et al.
Secular increase and geographical differences in hip fracture incidence in Norway
Bone
(1993) - et al.
Changing incidence of hip, distal radius, and proximal humerus fractures in Tottori Prefecture, Japan
Bone
(1999) - et al.
The changing picture of hip fracturesDramatic change in age distribution and no change in age-adjusted incidence within 10 years in central Finland
Bone
(1999) - et al.
Hip fractures in Finland between 1970 and 1997 and predictions for the future
Lancet
(1999) - et al.
Effect of external hip protectors on hip fractures
Lancet
(1993) - et al.
Bone
(1995) - et al.
Statistical Methods in Medical Research
(1994) - et al.
International comparison of hip fracture rates in 1988–89
Osteopor Int
(1996) - et al.
Fractures of the proximal femur in Picardy, France, in 1987
Osteopor Int
(1993) Epidemiology of osteoporosis
Osteopor Int
(1999)