B B THE ROLE OF ALCOHOL AND DRUGS IN BICYCLE ACCIDENTS IN FINLAND

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1 1987 Elsevier Science Publishers B.V. (Biomedical Division) Alcohol, drugs and traffic safety T86 P.C. Noordzij and R. Roszbach, editors. B THE ROLE OF ALCOHOL AND DRUGS IN BICYCLE ACCIDENTS IN FINLAND SEPPO OLKKONEN, UOLEVI LAHDENRANTA, JORMA TOLONEN AND RISTO HONKANEN Research Institute of Public Health, University of Kuopio, Department of Orthopedics and Traumatology Helsinki University Central Hospital, Finland INTRODUCTION The bicycle accidents play a growing role among all traffic accidents in Finland. According to the OECD report there was the third highest number of bicycles per inhabitant in Finland after Denmark and the Netherlands in the year 1974 (1). The proportion of bicycle accidents of all fatal traffic casualties increased from 12% to 19% during the years in Finland. According to official records in 1983 there were 99 fatal and 1643 injured casualties in bicycle accidents. Alcohol was involved in 13,1 % of fatal and in 5,6% of injured cases (2,3). Police records covered only a fraction of nonfatal bicycle accidents. Alcohol intoxication is regarded as one of the most important causes of accidents. Also therapeutic doses of several drugs have been shown to impair psychomotor skills related to driving. Tolonen et al (4) detected clinically alcohol positive patients in the casualties of the road traffic accidents as follows: Pedestrians 18,6%, car drivers 4,8% and bicyclists 7,9%. Controlled studies on the accident risk related to use of alcohol and drugs among car drivers and pedestrians (5,6,7) indicate that alcohol increases a pedestrians risk of accidental fall somewhat more than driver's risk of traffic accident. Epidemiological studies on the role of drugs and alcohol in the bicycle accidents are few. Our hypothesis was that alcohol raises bicycle accident risk more than pedestrian's risk of accidental fall or drivers of traffic accident, as biking places higher reguirements for psychomotor skills than either walking or driving. The aim of our study was to assess the accident risk of bicycling under the influence of alcohol or drugs. B 25900

2 284 MATERIALS AND METHODS 1) The unmatched case-control designed study was conducted during two months, from 1 May to 30 June 1986 in Helsinki. Cases. In order to increase the effectiveness of the study adult patients (16 years of age or older) and evening accidents were selected. The casualties were treated within 6 hours after the bicycle accident occured. The cases were recorded in the emergency wards of three hospitals in Helsinki: the Toolo and Surgical Hospitals (The Ith and IVth Dep.of Surgery of Helsinki Univ. Central Hospital) and as well as the Malmi Hospital. These hospitals care over 90% of the accident patients in Helsinki. Health disorders and the use of drugs were recorded with a questionnaire. Visual acuity was measured by a screening test. Blood alcohol was measured with the Alcotest breath analyzer. Controls. It was decided to select about 700 controls on fourteen days whichs were randomly chosen from the 61 case selection days. Four one-hour control selection periods between 3-10 P.M. on each day were chosen. Twenty eight control selection sites and the number of controls in each were chosen in proportion to the number of inhabitants and the rate of bicycling by day of week, hour of day and area of the city of Helsinki (8).The bicyclist were randomly stopped by a police officer, who also made the breath analysis test. The decision to select a control cyclist was made before he was in sight. The cyclists were interviewed by the author or an assistant similarly as cases at hospitals. The visual acuity was also screened of the controls. 2)A five month study of bicycle accident casualties in the Toolo Hospital (Helsinki) in the year 1985 (lmay-30september). To record the use of drugs or alcohol a questionnaire was used. 3)One year data files of alcohol positive bicycle accident cases during the year 1983 at the Toolo Hospital.The breath test was made if there were signs of alcohol consumption. 4)One year epidemiological study from Eastern Finland The influence of alcohol to the non motor vehicle bicycle accidents were estimated by the questionnaire filled by the patient and the helping nurse.

3 RESULTS 1) In the case-control study there were 89 patients. The breath test was not recorded from 17 patients (19%). The number of controls was 700, of these breath test was not recorded in 29 cyclists (4,1%). Twenty-six (3,7%) cyclists refused to stop for the interview. They were usually in a hurry to somewhere ( to work,bank,shop, etc). New control cyclists were chosen instead of them. The mean age of the cases and the controls was 36 and 35 yr. respectively. However, alcohol positive controls were older than alcohol positive cases (43 and 39 yr. resp.). Alcohol involvement. A profound difference in alcohol involvement rates was found: 20,3% of the cases and 1,9% of the controls with known breath analysis had blood alcohol concentration (BAC) above 0,4 9g/l (Table 1.). High BACs were overrepresented in the case and low BACs in the control series. Drugs. Sixteen percent of the cases and 13% of the controls had used a drug on the day of the interview. There was no difference in use of warning triangel medicines (9) among patients and controls. The mean age of the drug users was higher among cases (52 yr.) than controls (42 yr.). Health disorders. A chronic health disorder was recorded in 12,o % of the patients and 2,1 % of the controls. Impairment in visual acuity was found in 9,0 % of the cases and in 1,6 % of the controls. Table 1. Patients, controls and risk of bicycle accident by blood alcohol concentration (BAC). BAC PATIENTS CONTROLS RELATIVE ( g/1 ) N (%) N (%) RISK 0 52 (58,4) 634 (90,6) 1,0 0,01-0,49 0 (0) 17 (2,4) - 0,50-1,49 3 (3,4) 6 (0,9) 6,1 1,50-3,00 15 (16,9) 7 (1,0) 26,1 Unknown 17 (19,0) 29 (4,1) 1 Total 89 (100,0) 700 (100,0)

4 286 2) In 1985 questionnaires were filled on 373 bicycle accident casualties at the Toolo Hospital. Of the patients 10,2% reported to have used alcohol within 6 hours and 4,6% within 6-24 hours before the bicycle accident. Five percent of the casualties had used a drug on the day of the accident. Medicines labeled with warning triangel (9) formed 1,6% of the drugs. 3) In 1983 there were at the Toolo Hospital 934 bicycle accident casualties. There were 7,2 % alcohol positive patients. Alcohol was involved in 4 % of motor-vehicle but in 7,9 % of non-motor-vehicle accidents. From the alcohol-positive patients 70% had BAC over 1,5 g/1 and most of them were men (73%). Of the alcohol positive patients 75% had arrived in hospital from 3 P.M. to 2 A.M.. 4) Medically attended bicycle accidents during one year (1 May April 1981) from the Mikkeli area were analyzed. Total number of bicycle accident casualties was 374. Motor vehicle - bicycle accidents formed 12%. Mean age of all patients was 27 years. Alcohol was reported by 3 % of patients from non-motor-vehicle accidents. CONCLUSION Alcohol is one of the causal factors in bicycle accidents. The accident risk seems to be more than twenty folded at BACs above 1,4 g/1.however, alcohol increased a bicyclists accident risk less than a pedestrian's risk of accidental fall (6). Use of drugs, on the other hand, does not seem to be a significant risk factor. Also poor health seem to be related to increased risk of bicycle accidents. ACKNOWLEDGEMENTS This study was financially supported by Liikennevakuutusyhdistys and Liikenneturva, Helsinki.

5 REFERENCES 1. Safety of two-wheelers (1978). A report prepared by an OECD Road Research Group, OECD, Paris, pp Road Traffic Accidents Statistical Repcprt No LI 1981:30. The Central Statistical Office of Finland, Helsinki, pp Road Traffic Accidents Statistical Report No LI 1984:23. The Central Statistical Office of Finland, Helsinki, pp 14,29 4. Tolonen J, Kiviluoto O, Santavirta S and Honkanen R (1983):Spesific Features in Road Traffic Injuries. Reports from Liikenneturva 26, Helsinki, pp 9,22 5. Honkanen R, Ertama L, Linnoilla M, Alha A, Lukkari J, Karlsson M, Kiviluoto O, Puro M (1980): Role of drugs in traffic accidents. Br Med J 281: Honkanen R, Ertama L, Kuosmanen P, Linnoila M, Alha A, Visuri T (1983): The Role of Alcohol in Accidental Falls. Journal of Studies on Alcohol. New Brunswick, NJ Vol 44, No2 pp Borkenstein RF. Crowther RF, Shumate RP, Ziel WB and Zylman R (1974): The role of the drinking driver in traffic accidents (The Grand Rapids Study) 2d ed Blutalkohol 11 (Suppl. No 1) Naskila A (1984): Kevyen liikenteen laskennat Helsingissa , maaria ja ominaisuuksia. Helsingin kaupunki, Kaupunkisuunnitteluvirasto, Liikennesuunnitteluosasto. Julkaisuja LB:8/84 9. Pharmaca Fennica laakevalmisteet 1986, Laaketeollisuusyhdistys ry, Helsinki