Epidemiology and prevention of bicycle-related injuries in Sweden

Abstract

The main objectives of the study are. to analyse injury patterns and trends in injuries among bicyclists at county and national levels in Sweden (with a primary focus on head injuries) and to develop methods for the analysis and prevention of bicycle-related injuries, including head injuries.

For children under 15 in Skaraborg County there. was an average annual decrease in all bicycle-related injuries of 3.1 %, equivalent to a decrease of 48 % over the period 1978- 93 (for head injuries 59 %). By contrast, the elderly, not targeted in helmet-wearing programs before. the mid-1990s, showed a significant increase (4.7% annually) (Paper 1). In a countywide program on increasing helmet use political and intersectoral support and information via the media were important process elements (Paper II). In Sweden's Western Region both bodily injuries in general and head injuries in particular show regional differences with the highest incidence in rural Skaraborg County. Females generally show a lower incidence than males, but older women are more. likely to be seriously injured than younger. Females sustain more. work-related bicycle injuries than males. All this indicates that targeted measures are. required (Paper 111).

There was 3.7 times greater risk of being killed in a bicycle-related accident for the elderly than for children 14 or under. Elderly showed an annual increase of 2.7 % for head injuries between 1987 and 1996, with an average annual increase in the south and north of Sweden of 2.2 % and 4.2 % respectively (Paper IV). For children there is a substantial difference in injury rates between urban (higher) and rural (lower) areas (Paper V). The north/south comparison does not give the same clear picture for small children, but for the. 7-14 olds.

The conclusion is that there. are a reasons to interpret the results as that a comprehensive bicycle helmet program decreases head injuries significantly more than single-factor oriented programs (Paper 1). However, methodological errors or changes in diagnostic procedures as well as hospital admission policies might explain part of the decrease of head injuries. Process evaluation of a county program support the conclusion that political participation, intersectoral cooperation as well as distribution of information via media, are important determinants of program success (Paper 11). Geographical, gender, age and occupational differences, leads to the conclusion that targeted measures are required. There are reasons to move. the. focus of preventive. activities also to adult cycling (Paper Ill, IV and V).

The general conclusion of these studies is that it has been possible to develop methods both for prevention of bicycle-related head injuries, and analysis of intervention programs. For head injuries the national hospital discharge registries can be used - with much caution - on county, regional as well as on national level. Future studies should concentrate on the quality control on such registries, as well as on the development of biostatistical methods for analysing trends. It is also important to develop qualitative methods that more clearly describes intervention efforts parallel to outcome results.