Helmet use and risk of head injuries in alpine skiers and snowboarders Excerpt below is based on: Sulheim S, Holme I, Ekeland A, Bahr R. Helmet Use and Risk of Head Injuries in Alpine Skiers and Snowboarders. JAMA. 2006;295:919-924 Background Alpine skiing and snowboarding are increasingly popular winter sports and are enjoyed by several hundred milion people worldwide. However, the injury risk is high, and head injuries are common. Helmets are strongly advocated to prevent head injuries in bicycling and in-line skating, and are mandatory for competitive skiers in the Fdration Internationale de Ski (FIS) World Cup events. In contrast, ski resorts do not typically require helmet use. In the absence of recommendations, helmet use is generally low among recreational skiers and snowboarders, although their use is higher among children. Opponents of mandatory helmet use claim that helmets may increase the risk because they may lead to a reduced field of vision, impaired hearing, or increased speed through a false feeling of security. Two recent epidemiological studies have assessed the effect of helmet use on the risk of head and neck injuries among skiers and snowboarders, but one study did not control for potentially important confounding factors, and the other used patients with injuries other than head injuries as their control group. The purpose of our study was to examine the effects of helmet use on the risk of head injury among skiers and snowboarders using an uninjured, representative group of skiers and snow-boarders as controls while adjusting for risk factors and potential confounders, such as age, equipment, ability, and sex. Methods Ski patrols and first aid staff at Norwegian ski resorts register the injuries they attend on the Norwegian Ski Lift Association injury and marketing research database. Cases of head injury for this study were identified from the database. Anonymised reports of injuries from 8 Norwegian ski fields were included. Ethical approval for this study was given by the Regional Committee for Medical Research Ethics of Southern Norway. An injury was recorded when a skier or snowboarder was treated by, or consulted with, the ski patrol or first aid room staff after an accident in the skiing area. A standard form was used to record personal data (age, sex, nationality), as well as information on the type of equipment used (alpine skis; Telemark skis, which permits a turning technique with free heel lift; snowboard, sleigh; or other), use of helmet (yeso), previous ski school attendance (yeso), rented or own equipment (yeso), and skiing ability. Skiing ability was classified into 4 categories (beginner, intermediate, good, or expert) based on self-reported performance. The anatomical location (head, neck, shoulder, etc) was also recorded. For patients with multiple injuries, each injury was recorded separately. As a control group, 2992 non-injured skiers and snowboarders were interviewed in the same 8 ski fields during the same season. The interviews were conducted at the entry to the bottom main ski lift at each fields. Every 10th skier or snowboarder waiting in line was interviewed to achieve a systematic sample of the population. The interviews were done every Wednesday and Saturday during the 4 winter months of 2002 to capture the differences between weekday and weekend skiers. The registration was done when lifts opened in the morning and after lunch (ie, 10-11 AM and 1-2 PM). Except for the injury-related information, the questions asked were the same as those for the injured skiers. Interviewers were not told the purpose of the study. Chi-squared tests were used to compare characteristics between groups. We used logistic regression to estimate the relationship between helmet use and head injuries, including all identified potential confounders in the model. Odds ratios (ORs) are presented with 95% confidence intervals (CIS). An a-level of 0.05 was considered to be statistically significant. Results Of the 3277 patients with injuries recorded on the data base, 578 (17.6%) had head injuries. Characteristics of people with and without head injuries are shown in Table 1. Table 2 compares the same characteristics with respect to helmet use or not within the control group. Table 3 shows the relationship between participant characteristics and risk of head injuries analysed using multiple logistic regression. P Valuet 4.001 .005 <.001 table comparison of helmet use frequency in various subgroups sloers and snowboarders the uninjured control group no.1 users nonusers characteristic age y>>20 248 (12.5% 1670 1871) Sex Male 427 (23.71 137417631 Farnale 229 18.4 95400.61 National Norwegian 397 24.23 Swedish 134 23.6 43476.41 Danish 97 (15.8 517184 21 C 13583.31 Sking abity Expert 184/22.33 22.3 398 187.71 Good 21720.61 838 79.4) Intermediate 851947) Berner 251172.1) ! Alpina sids 388 (20.2 1467 179.81 Snowboard 200 (27.5 54917251 49 (18.21 25418381 Used rented pient Yes 169 (204 6537961 ND 487 22.6 1689177.41 Sking instruction Yes 277 27.6 718172.11 NO 379 (19.11 1809 80.91 Denominators may vary due to missing values Chi-squared ast <.001 table comparison between scers and snowboarders with head injuries controls number of participants characteristic p value viure helme np unknown aco in years>20 237 (410) 1919 (64.1) Unknown 12 (2.1) ) 12 (0.4) -0.002 Sex Male 388 (67.1) 1801 (602) Famale 188 (325) 1185 (396) Unknown 2 (0.3) 6 (0.2) 0.001 Nationality Norwegian 347 (60.0) 1639 (548) Swedish 80 (13.a) 569 (19.0) Danish 106 (18.3) 615 (206) Other 45 (7.8 162 (5.4) C.002 Unknown 7 ( 7 (0.2) Skiing ability Expert 108 (187) 570 (19.1) Good 186 (32.2) 1055 (353) Intermediate 147 (254) 1005 (33.5) Beginner 123 (213) 348 (11.6) 0.001 Unknown 14 (24) 14 (0.5 Equipment Alpine skis 288 (498) 1827 (61.1) Snowboard 248 (42.9 757 (253) Telerark skis 32 (5.5) 303 (10.1) 0.001 Unknown 10 (13) 84 (2) Used rented equipment Yes 164 (284) 829 (277) No 402 (69.6) 2157 (72.1) 0.56 Unknown 12 (2.1) 6 (0.2) Skiing instruction Yes 182 (31.5) 993 (33.2) No 362 (630) 1990 (66.5) Unknown 32 (5.5) 0.98 4.001 Talemak 34 254 .20 <.001 table multiple logistic regression analyses of relationship between head injury and potential confounding risk factors unadjusted or adjusted variables ci p value helmet use without with abbreviations: odds ratio cl confidence interval for age sex nationality skiing ability equipment percentages may not sum to clue rounding from chi-squared lots excluding unknown h the authors did give response rates controls. if those who were willing take part in study more likely than non-respondents wear helmets how might that bias estimate association explain your reasoning. answer this question at most words. i describe one source information either data whether you think could have affected injury. j a criticism was duration taken into account. lead estimated injuries alpine skiers snowboarders excerpt below is based on: sulheim s holme ekeland bahr r. snowboarders. jama. background snowboarding are increasingly popular winter sports enjoyed by several hundred milion people worldwide. however high common. strongly advocated prevent bicycling in-line skating mandatory competitive fdration internationale de ski world cup events. contrast resorts do typically require use. absence recommendations generally low among recreational although their higher children. opponents claim increase because they reduced field vision impaired hearing increased speed through false feeling security. two recent epidemiological studies assessed effect on neck but control potentially important other used patients as group. purpose our examine effects using an uninjured representative group snow-boarders controls while adjusting confounders such sex. methods patrols first aid staff norwegian register attend lift marketing research database. cases identified anonymised reports fields included. ethical approval given regional committee medical ethics southern norway. recorded when skier snowboarder treated consulted patrol room after accident area. standard form record personal well type skis telemark which permits turning technique free heel snowboard sleigh previous school attendance rented own ability. classified categories intermediate good expert self-reported performance. anatomical location shoulder etc also recorded. each separately. non-injured interviewed same during season. interviews conducted entry bottom main fields. every waiting line achieve systematic sample population. done wednesday saturday months capture differences weekday weekend skiers. registration lifts opened morning lunch am pm except injury-related questions asked injured interviewers told study. tests compare characteristics groups. we including all model. ratios presented intervals a-level considered be statistically significant. results base had injuries. shown compares respect within shows participant analysed regression. valuet .005 comparison frequency various subgroups sloers no.1 users nonusers characteristic y>>20 248 (12.5% 1670 1871) Sex Male 427 (23.71 137417631 Farnale 229 18.4 95400.61 National Norwegian 397 24.23 Swedish 134 23.6 43476.41 Danish 97 (15.8 517184 21 C 13583.31 Sking abity Expert 184/22.33 22.3 398 187.71 Good 21720.61 838 79.4) Intermediate 851947) Berner 251172.1) ! Alpina sids 388 (20.2 1467 179.81 Snowboard 200 (27.5 54917251 49 (18.21 25418381 Used rented pient Yes 169 (204 6537961 ND 487 22.6 1689177.41 Sking instruction Yes 277 27.6 718172.11 NO 379 (19.11 1809 80.91 Denominators may vary due to missing values Chi-squared ast <.001 table comparison between scers and snowboarders with head injuries controls number of participants characteristic p value viure helme np unknown aco in years>20 237 (410) 1919 (64.1) Unknown 12 (2.1) ) 12 (0.4) -0.002 Sex Male 388 (67.1) 1801 (602) Famale 188 (325) 1185 (396) Unknown 2 (0.3) 6 (0.2) 0.001 Nationality Norwegian 347 (60.0) 1639 (548) Swedish 80 (13.a) 569 (19.0) Danish 106 (18.3) 615 (206) Other 45 (7.8 162 (5.4) C.002 Unknown 7 ( 7 (0.2) Skiing ability Expert 108 (187) 570 (19.1) Good 186 (32.2) 1055 (353) Intermediate 147 (254) 1005 (33.5) Beginner 123 (213) 348 (11.6) 0.001 Unknown 14 (24) 14 (0.5 Equipment Alpine skis 288 (498) 1827 (61.1) Snowboard 248 (42.9 757 (253) Telerark skis 32 (5.5) 303 (10.1) 0.001 Unknown 10 (13) 84 (2) Used rented equipment Yes 164 (284) 829 (277) No 402 (69.6) 2157 (72.1) 0.56 Unknown 12 (2.1) 6 (0.2) Skiing instruction Yes 182 (31.5) 993 (33.2) No 362 (630) 1990 (66.5) Unknown 32 (5.5) 0.98 4.001 Talemak 34 254 .20 <.001 table multiple logistic regression analyses of relationship between head injury and potential confounding risk factors unadjusted or adjusted variables ci p value helmet use without with abbreviations: odds ratio cl confidence interval for age sex nationality skiing ability equipment percentages may not sum to clue rounding from chi-squared lots excluding unknown h the authors did give response rates controls. if those who were willing take part in study more likely than non-respondents wear helmets how might that bias estimate association explain your reasoning. answer this question at most words. i describe one source information either data whether you think could have affected injury. j a criticism was duration taken into account. lead estimated words>