Emergency department coding of bicycle and pedestrian injuries during the transition from ICD-9 to ICD-10.

BACKGROUND: The international classification of diseases version 10 (ICD-10) uses alphanumeric expanded codes and external cause of injury codes (E-codes). OBJECTIVE: To examine the reliability and validity of emergency department (ED) coders in applying E-codes in ICD-9 and -10. METHODS: Bicycle and pedestrian injuries were identified from the ED information system from one period before and two periods after transition from ICD-9 to -10 coding. Overall, 180 randomly selected bicycle and pedestrian injury charts were reviewed as the reference standard (RS). Original E-codes assigned by ED coders (ICD-9 in 2001 and ICD-10 in 2004 and 2007) were compared with charts (validity) and also to ICD-9 and -10 codes assigned from RS chart review, to each case by an independent (IND) coder (reliability). Sensitivity, specificity, simple, and chance-corrected agreements (κ statistics) were calculated. RESULTS: Sensitivity of E-coding bicycle injuries by the IND coder in comparison with the RS ranged from 95.1% (95% CI 86.3 to 99.0) to 100% (95% CI 94.0 to 100.0) for both ICD-9 and -10. Sensitivity of ED coders in E-coding bicycle injuries ranged from 90.2% (95% CI 79.8 to 96.3) to 96.7% (95% CI 88.5 to 99.6). The sensitivity estimates for the IND coder ranged from 25.0% (95% CI 14.7 to 37.9) to 45.0% (95% CI 32.1 to 58.4) for pedestrian injuries for both ICD-9 and -10. CONCLUSION: Bicycle injuries are coded in a reliable and valid manner; however, pedestrian injuries are often miscoded as falls. These results have important implications for injury surveillance research.

Impact of AIDS on mortality in San Francisco, 1979-1986.

We used death certificate data for San Francisco residents from 1979 to 1986 to calculate the number of deaths and years of potential life lost before age 65 (YPLL) for leading causes of death. Acquired immune deficiency syndrome (AIDS)-related deaths were defined as including cytomegalovirus infection (ICD-9 078.5); cryptococcal infection (ICD-9 117.5); Pneumocystis carinii pneumonia (ICD-9 136.3); other malignant neoplasms of the skin, site unspecified (ICD-9 173.9); deficiency of cell-mediated immunity (ICD-9 279.1); and unspecified immunity deficiency (ICD-9 279.3). These deaths increased from 5 (0.1% of all deaths) in 1979 to 534 (6.6%) in 1986. Of the 1,225 deaths caused by AIDS-related diseases during this period, 1,032 (84%) occurred in men aged 20-49 years. AIDS-related deaths increased between 1979 and 1986 from 0 to 44 (25% of all deaths), 0 to 257 (44%), and 0 to 150 (35%) in men aged 20-29 years, 30-39 years, and 40-49 years, respectively. In 1986, AIDS-related diseases were the third leading cause of deaths and the leading cause of YPLL among male San Francisco residents.

Kaposi's sarcoma reporting in San Francisco: a comparison of AIDS and cancer surveillance systems.

A preliminary comparison of the reported incidence of Kaposi's sarcoma among males under 60 years of age residing in San Francisco was conducted using merged San Francisco AIDS Registry and California Tumor Registry (CTR) data. For the years 1980-1986, the number of cases reported by both registries was similar. However, only 961 (72.3%) of the 1,330 cases appearing in either registry appeared in both. Of the 160 Kaposi's sarcoma cases in the AIDS registry only, 11 (6.9%) were included in the CTR with another cancer diagnosis. Of the 209 Kaposi's sarcoma cases occurring only in the CTR, 109 (52.2%) were included in the AIDS registry with another diagnosis. The number of cases included in either or both registries was about 20% more than in either alone. Data sharing between the staff of these registries is precluded by confidentiality constraints.

Dealing with missing data in observational health care outcome analyses.

Observational outcome analyses appear frequently in the health research literature. For such analyses, clinical registries are preferred to administrative databases. Missing data are a common problem in any clinical registry, and pose a threat to the validity of observational outcomes analyses. Faced with missing data in a new clinical registry, we compared three possible responses: exclude cases with missing data; assume that the missing data indicated absence of risk; or merge the clinical database with an existing administrative database. The predictive model derived using the merged data showed a higher C statistic (C = 0.770), better model goodness-of-fit as measured in a decile-of-risk analysis, the largest gradient of risk across deciles (46.3), and the largest decrease in deviance (-2 log likelihood = 406.2). The superior performance of the enhanced data model supports the use of this "enhancement" methodology and bears consideration when researchers are faced with nonrandom missing data.

Nedocromil sodium for preventing exercise-induced bronchoconstriction.

BACKGROUND: Exercise-induced asthma causes cough, dyspnea, wheeze and chest tightness. Management of focuses on prevention through pharmaco-therapy and alternate strategies. Single use, pre-exercise beta2-agonists and non-steroidal anti-inflammatory agents such as the cromones are the most common treatments. OBJECTIVES: The objective of this review was to assess the effects of a single dose of nedocromil sodium to prevent exercise-induced bronchoconstriction. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register, the Cochrane Controlled Trials Register, Current Contents, review articles, textbooks and reference lists of articles. We also contacted the drug manufacturer and primary authors for additional citations. SELECTION CRITERIA: Randomised trials comparing a single dose of nedocromil sodium with placebo to prevent exercise-induced bronchoconstriction in people over six years of age. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were conducted independently by two reviewers. Study authors were contacted for confirmation of data. MAIN RESULTS: Twenty randomised controlled trials involving 280 participants were identified. 15-60 min following inhalation of 4 mg nedocromil, the maximum fall in forced expiratory volume in one second due to exercise was improved by 15.6%, (95% CI:13.2 to 18.1) compared to the placebo response. The maximum percentage fall in peak expiratory flow rate was of the same magnitude (weighted mean difference 15.0%; 95% CI 8.3 to 21.6). Nedocromil shortened the time to recover lung normal function from more than 30 minutes with placebo to less than 10 minutes with the drug. The relative magnitude of its effect was greatest in patients with more severe exercise-induced bronchoconstriction (defined as an exercise-induced fall in lung function > 30% from baseline). There were no significant adverse effects reported. REVIEWER'S CONCLUSIONS: Nedocromil sodium used before exercise appears to reduce the severity and duration of exercise-induced bronchoconstriction. This effect appears to be more pronounced in people with severe exercise-induced bronchoconstriction.

Nedocromil sodium for preventing exercise-induced bronchoconstriction.

BACKGROUND: Exercise-induced bronchoconstriction (EIB) following strenuous physical exertion afflicts many people. It can be the cause of sub-optimal performance, symptoms such as cough, dyspnea, wheeze and chest tightness, and can lead people to avoid physical activity. Management of EIB focuses on prevention through pharmaco-therapy and alternate strategies. Single use, pre-exercise, beta-agonists and non-steroidal antiinflammatory agents are recommended. OBJECTIVES: Bronchodilator medications have been commonly used to prevent narrowing of airways after exercise, but anti-inflammatory drugs such as nedocromil sodium have also been used. The objective of this review was to assess the effects of a single dose of nedocromil sodium to prevent exercise-induced bronchoconstriction. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register, the Cochrane Controlled Trials Register, Current Contents, review articles, textbooks and reference lists of articles. We also contacted the drug manufacturer and primary authors for additional citations. SELECTION CRITERIA: Randomised trials comparing a single dose of nedocromil sodium with placebo to prevent exercise-induced bronchoconstriction in patients with EIB over six years of age. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were conducted independently by two reviewers. Study authors were contacted for confirmation of data. MAIN RESULTS: The combined results from 20 randomised controlled trials involving 280 participants, show that 4 mg, of nedocromil sodium inhaled 15 to 60 minutes prior to exercise significantly reduce the severity and duration of EIB in both adults and children, when compared to placebo. The maximum percentage fall in FEV1 was improved significantly compared to placebo (weighted mean difference 15.5 %; 95% confidence interval:13.2 to 18.1). For the maximum percentage fall in peak expiratory flow rate (PEFR) the improvement was similar: WMD 15.0%, (95% CI 8.3 to 21.6). Nedocromil shortened the time to recover lung normal function from more than 30 minutes with placebo to less than 10 minutes with the drug. It had a greater effect on those patients with more severe exercise-induced bronchoconstriction (defined as an exercise-induced fall in lung function > 30% from baseline). There were no significant adverse effects reported with the short term use of nedocromil. A further search conducted in September 2001 did not yield any further studies. REVIEWER'S CONCLUSIONS: Nedocromil sodium used before exercise reduces the severity and duration of exercise-induced bronchoconstriction. This effect appears to be more pronounced in people with severe exercise-induced bronchoconstriction.

Inhaled steroids in acute asthma following emergency department discharge.

BACKGROUND: Patients with acute asthma treated in the emergency department are frequently treated with inhaled beta-agonists and corticosteroids (CS) after discharge. The use of inhaled CS (ICS) following discharge may also be beneficial in acute asthma. OBJECTIVES: To determine the effect of inhaled corticosteroids (ICS) on outcomes in the treatment of acute asthma following discharge from the emergency department (ED). SEARCH STRATEGY: Randomised controlled trials (RCTs) were identified from the Cochrane Airways Review Group register which consists of systematic searches of EMBASE, MEDLINE and CINAHL databases supplemented by hand searching of 20 respiratory journals. In addition, abstracts from conferences were searched; primary authors and pharmaceutical companies were contacted to identify eligible studies. Bibliographies from included studies, known reviews, and texts also were searched. SELECTION CRITERIA: Only RCTs or quasi RCTs were eligible for inclusion. Studies were included if patients were treated for acute asthma in the ED or its equivalent, and following ED discharge were treated with ICS therapy either in addition to, or as a substitute for, oral corticosteroids (CS). Two reviewers independently assessed articles for potential relevance, final inclusion, and methodological quality - to "expand" the search. We didn't include any in the end) DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers if the authors were unable to verify the validity of information. Several authors and pharmaceutical companies provided unpublished data. The data were analysed using the Cochrane Review Manager 4.0.4. MAIN RESULTS: Ten trials were selected for inclusion. Three of these trials, involving a total of 909 patients, compared ICS plus CS Vs CS therapy alone. There was no demonstrated benefit of ICS therapy when used in addition to CS therapy in the trials. Relapses were reduced, but not significantly, with the addition of ICS therapy (OR: 0.68; 95% CI: 0.46 to 1.02). As well, no differences were demonstrated between the two groups for relapses requiring admission, quality of life, symptom scores, or adverse effects. Seven trials, involving a total of 1204 patients, compared high-dose ICS therapy alone Vs CS therapy alone after ED discharge. There were no significant differences demonstrated between ICS therapy alone and CS therapy alone for relapse rates (OR: 1.00; 95% CI: 0.66 to 1.52) or in the secondary outcomes of beta-agonist use, symptoms, or adverse events. However, the sample size was not adequate to confidently exclude the possibility of either treatment being significantly inferior, and severe asthmatics were excluded from these trials. REVIEWER'S CONCLUSIONS: There is insufficient evidence that ICS therapy provides additional benefit when used in combination with standard CS therapy upon ED discharge for acute asthma. There is some evidence that high-dose ICS therapy alone may be as effective as CS therapy when used in mild asthmatics upon ED discharge; however, there is a significant possibility of a type II error in drawing this conclusion. Further research is needed to clarify whether ICS therapy should be employed in acute asthma treatment in the ED or following ED discharge.

Preeclampsia and cerebral palsy in low-birth-weight and preterm infants: implications for the current "ischemic model" of preeclampsia.

OBJECTIVE: One of the prevailing hypotheses for the pathogenesis of preeclampsia is the "ischemic model." It assumes that reduced uteroplacental perfusion is the primary step and the point of convergence of diverse pathogenic processes in the development of preeclampsia. One might expect a fetus under such "ischemic conditions" to be at an increased risk of later development of cerebral palsy (CP). The objective of this study was to test the hypothesis that maternal preeclampsia increases the risk of CP in preterm and low-birth-weight infants. METHODS: A meta-analysis was performed based on published articles identified by searching computerized databases (MEDLINE, EMBASE, CINAHL, Current Contents, Biological Abstracts, and Dissertation Abstracts) from 1966 through 1999. Ten observational studies on the association between preeclampsia and CP were identified based on prespecified inclusion criteria. Two independent reviewers extracted data and assessed the methodological quality of eligible articles. Odds ratios (OR) of CP for preeclampsia from individual studies were pooled. MAIN OUTCOME MEASURE: Cerebral palsy. RESULTS: In case-control studies, preeclampsia was associated with a statistically significant decreased risk of CP [pooled adjusted OR, 0.50; 95% confidence interval (CI), 0.33-0.81; p < 0.01). In cohort studies, preeclampsia was associated with a nonstatistically significant reduced risk of CP (pooled OR, 0.91; 95% CI, 0.35-2.41; p > 0.05). CONCLUSIONS: Preeclampsia may be associated with a decreased risk of CP in preterm and low-birth-weight infants. This challenges the currently held belief that reduced uteroplacental perfusion is the unique pathophysiological process in preeclampsia.

Survey of local environmental health programs in Alberta.

As part of a larger initiative to develop a contemporary model for local environmental health services, a survey of Alberta health unit-based programs was undertaken. The objectives were to (a) obtain a comprehensive profile of environmental health services, and (b) identify current and emerging issues in these programs. Three survey instruments were designed for three respondent groups: chief executive officers, program managers and environmental health officers/public health inspectors. Results suggest an expanding scope of activities and issues faced by these programs. The most prevalent emerging issues noted were in the areas of chemical/ toxic exposures, injury prevention, indoor air quality and public risk perception. Issues receiving the greatest attention were food safety and waste management. Review of program management capacities suggested difficulties in coping with the increased pressures faced by these programs. Improvements recommended by respondents included increased resources, more educational and professional development opportunities, improved information systems and improved legislation.

Unintentional house fire deaths in Alberta 1985-1990: a population study.

We extracted data from the Medical Examiner's files for all fire deaths in Alberta reported to the Medical Examiner's for the period 1985-1990. Of the 320 fire deaths, 183 (57%) were unintentional deaths from house fires. The highest house fire death rates occurred in children 0-4 years and in adults > or = 80 years of age (2.9 and 3.2 per 100,000 per year). The majority (53%) of fatal house fires occurred in single detached dwellings but the rate of fatal house fires was 9.0 times higher in moveable dwellings than in single detached dwellings. At least 61 (33%) of unintentional fatal house fires were caused by smokers' material. Blood alcohol levels above 0.8 g/L were found in 84 (59%) of victims tested and in 39 (76%) of victims of fires caused by smoking materials. 143 (78%) house fire deaths were due, at least in part, to inhalation of toxic fumes. The cause of fatal house fires in Alberta is multifactorial. However, particular attention should be paid towards the lethal combination of cigarettes and alcohol in preventing these fires.

Cost effectiveness of Streetworks' needle exchange program of Edmonton.

OBJECTIVE: To conduct a cost-effectiveness analysis of the Edmonton Streetworks needle exchange program, in terms of the additional cost per HIV infection averted. The main outcome measures were needle use with and without Streetworks, HIV cases averted, and program costs. METHODS: We conducted interviews and HIV saliva tests on a sample of street-involved intravenous drug users (IDU) who are regular Streetworks' clients. Outcomes were used in a cost-effectiveness model. RESULTS: It is projected that the program has a cost-effectiveness of $9,500 (Canadian) per HIV infection delayed for one year. CONCLUSIONS: The discounted cost per case averted is less than the cost of a case of AIDS. Continuing the program is a dominant strategy.

Acute care hospital morbidity in the Blood Indian Band, 1984-87.

Acute care hospital morbidity of the Blood Indian Band was compared with that of all Albertans between April 1, 1984 and March 31, 1987. The Blood Indians had over 2.5 times as many hospital separations and 2.2 times as many patient days as the Albertans. The highest separation rare ratios by ICD-9-CM chapter for both Blood males and females were for endocrine, metabolic and nutritional disorders. Blood females had higher rate ratios for hospitalizations for all chapters except neoplasms and Blood males had higher rate ratios for all except congenital anomalies and neoplasms. For individual conditions, Blood males had the highest separation rate ratios for alcohol dependence syndrome, gastritis/duodenitis and diabetes mellitus. Bronchitis/emphysema and diabetes mellitus had the highest rate ratios for Blood females. The results are consistent with those reported in other studies of North American Indians. Their health status is more consistent with a developing country than that expected in Canada and does not appear to be improving.

Gestational diabetes mellitus: prevalence, risk factors, maternal and infant outcomes.

OBJECTIVES: To study prevalence, risk factors, and maternal and infant outcomes of women with gestational diabetes mellitus (GDM). METHODS: A retrospective cohort study was performed based on 111563 pregnancies delivered between 1991 through 1997 in 39 hospitals in northern and central Alberta, Canada. Multivariate logistic regression was used to estimate the odds ratios with 95% confidence intervals, and to control for confounding variables. RESULTS: The prevalence of GDM was 2.5%. Risk factors for GDM included age >35 years, obesity, history of prior neonatal death, and prior cesarean section. Teenage mothers and women who drank alcohol were less likely to have GDM. Mothers with GDM were at increased risk of presenting with pre-eclampsia, premature rupture of membranes, cesarean section, and preterm delivery. Infants born to mothers with GDM were at higher risk of being macrosomic or large-for-gestational-age. CONCLUSIONS: Specific conditions predispose to GDM which itself is associated with a significantly increased risk of maternal and fetal morbidity.

Maternal smoking and preeclampsia.

OBJECTIVE: To study the relationship between maternal smoking and preeclampsia and whether this association differs between primiparous and multiparous women. STUDY DESIGN: We conducted a population-based, retrospective, cohort study of 58,216 singleton pregnancies from northern and central Alberta, Canada, between 1995 and 1997. Multivariate logistic regression was used to control for maternal alcohol consumption, drug dependence, maternal age, maternal weight, prior intrauterine growth restriction and other confounders. RESULTS: Maternal smoking was associated with a significantly reduced overall risk of preeclampsia (adjusted odds ratio [aOR]: .61; 95% confidence interval [CI]: .50-.75; P < .01). Stratified analyses showed that in primiparous pregnancies, maternal smoking was associated with a significantly decreased risk (aOR: .63; 95% CI: .50-.80; P < .01); in multiparous women, maternal smoking was not associated with a statistically significant decreased risk of preeclampsia (aOR: 0.72; 95% CI: .51-1.02; P > .05). CONCLUSION: Maternal smoking is protective against preeclampsia. Understanding the underlying biologic mechanisms of this protective effect may advance our knowledge of the pathogenesis of preeclampsia.

Pesticide food poisoning from contaminated watermelons in California, 1985.

Aldicarb, a carbamate pesticide, is the most potent pesticide in the market and has a LD50 of 1 mg/kg. In the United States it is illegal to use aldicarb on certain crops, e.g., watermelons, because it is incorporated into the flesh of the fruit. Once an accidental or illegal use of such a potent pesticide occurs, there is no easy way for the agricultural or public health system to protect the populace. This paper describes the impact of one such event upon the health of individuals and the institutions of California. On July 4, 1985, California and other western states experienced the largest known outbreak of food-borne pesticide illness ever to occur in North America. This was attributed to watermelons contaminated through the illegal or accidental use of aldicarb by a few farmers in one part of the state. Within California, a total of 1,376 illnesses resulting from consumption of watermelons was reported to the California Department of Health Services (CDHS). Of the 1,376 illnesses, 77% were classified as being probable or possible carbamate illnesses. Many of the case reports involved multiple illnesses associated with the same melon among unrelated individuals. Seventeen individuals required hospitalization. There were 47 reports of illness involving pregnant women, two of whom reported having subsequent stillbirths. Thirty-five of the remaining pregnant women were followed-up 9 mo after the epidemic; no additional stillbirths were found.(ABSTRACT TRUNCATED AT 250 WORDS)

Socioeconomic risk factors and population-based regional allocation of healthcare funds.

Using the notion of professional uncertainty a population-based proxy need measure for hospital services was developed. Its relationship with socioeconomic variables and Standardized Mortality Ratios (SMR) was investigated in an attempt to develop an adjustment factor for socioeconomic risk factors beyond age-sex adjustment to be used for a population-based healthcare funding formula for Alberta. The data used are 1990, 1991, 1992 vital statistics and hospital separation abstracts, 1991 census data and Refined Diagnosis Related Group (RDRG) case weights. Geographic units studied were the 26 federal electoral districts in Alberta using postal codes as a linkage geo-code between census and hospital utilization and death data. SMRs, age-sex standardized per capita hospital utilization and proxy need rates were derived and correlated with socioeconomic variables derived from the census files. It appears that the poor, the less educated and aboriginals need more hospital services than the affluent, employed and educated, confirming previous findings. The unemployed tend to need more but use fewer services while immigrants and non-white ethnics tend to need and use fewer services. The unemployed, less educated and non-white ethnics are associated with positive correlation with premature mortality (SMR based on deaths under age 75 years), while the employed, highly educated tend to live longer. In general SMRs have positive but very low correlations with utilization and need rates suggesting that SMRs should not be used for resource allocation. Stepwise multiple regression analyses showed that the percentages of unemployed, immigrants, non-whites, aboriginals and those with education less than grade 9 explain about 90% of the variation in age-sex standardized hospital utilization rates. Percentages of unemployed, non-white ethnics, residents with education less than grade 9 and aboriginals explained 71% of variations in age-sex standardized per capita proxy hospital service need measures. Based on the results of regression analyses, a SEAM (Socio-Economic Adjustment Multiplier) scale was developed for utilization (SEAM-U) and proxy needs (SEAM-N). In essence a SEAM is a set of relative value (RV) multipliers applicable to a provincial common per age-sex adjusted capita allocation value to account for the impact of socioeconomic risk factors on hospital service needs or utilization. Finally, the resulting regression equations derived from the 26 Federal electoral district data were applied to Alberta's health regions, regional SEAMs were derived, and the impact of such adjustment was assessed.

Toward a framework for health service research.

Fiscal concerns have provided the impetus for wide-ranging attempts to reform the delivery of health care in Canada. Health reform has in turn stimulated great interest and activity in health service research. For health service research to be of maximum use in addressing current and future challenges to the health care system, closer liaison is needed between researchers and decision makers--the users of research. The purpose of this paper is to promote greater interaction between decision makers and researchers by proposing a framework for health predicated on types of information needed for decision-making rather than on study methodologies. We distinguish between decision makers at the societal, health system, program and service levels. Types of studies are classified by their purpose and by the phase of the management cycle for which they provide information for decision-making.

Considerations for regional health authorities in the provision of environmental health services.

As population health programs, environmental health services differ fundamentally from other forms of health service delivery. At a time when the health sector is striving for integration, the incorporation of these unique services into the delivery system presents a unique challenge to policy makers and administrators across the country. The University of Alberta recently completed a comprehensive review and redesign of locally governed and delivered environmental health protection services in Alberta. This paper outlines the key issues and unique features surrounding the delivery of environmental health services and presents the study team's suggested approach to addressing these issues.

Regionalization and hospital utilization: Alberta 1991/2-1996/7.

BACKGROUND: In February 1994 Alberta Health announced a three-year business plan for the radical restructuring of the health care system in Alberta. The business plan outlined large reductions in funding for acute hospital care spending and the establishment of 17 Regional Health Authorities (RHAs). OBJECTIVES: The objectives of this study are to describe for the period 1991/2 to 1996/7: 1) Trends in overall acute hospital utilization by Alberta residents and residents of each of the 17 RHAs. 2) Trends in the provision of acute hospital services by each of the 17 RHAs and the Alberta Cancer Board. 3) Trends in the transfer of patients between RHAs. RESULTS: Between 1991/2 and 1996/7, the age-sex standardized separation rate, the age-sex standardized average length of stay, and age-sex standardized hospital days rate for Alberta residents fell by 25.6%, 18.7%, and 39.5% respectively. The age-standardized hospital days rate fell in all 17 RHAs. The total number of separations (Alberta residents and non-residents) from Alberta acute care facilities fell by 19.6% while the average care intensity for all separations from Alberta acute care facilities rose by 8.7%. The ratio of the highest to lowest average RHA care intensity remained between 1.7 and 1.9 during the study period. RHA self-sufficiency indices increased dramatically in one RHA and remained largely unchanged in the remaining RHAs. RHA import indices decreased for most RHAs. CONCLUSIONS: Large reductions in the use of acute hospital services have occurred in Alberta during the period of major health care restructuring. Further research is needed to examine shifts in services to other sectors and to assess the impact of these reductions on patient outcomes.

Bicycle helmet use four years after the introduction of helmet legislation in Alberta, Canada.

BACKGROUND: Bicycle helmets reduce fatal and non-fatal head and face injuries. This study evaluated the effect of mandatory bicycle helmet legislation targeted at those less than 18 years old on helmet use for all ages in Alberta. METHODS: Two comparable studies were conducted two years before and four years after the introduction of helmet legislation in Alberta in 2002. Bicyclists were observed in randomly selected sites in Calgary and Edmonton and eight smaller communities from June to October. Helmet wearing and rider characteristics were recorded by trained observers. Poisson regression adjusting for clustering by site was used to obtain helmet prevalence (HP) and prevalence ratio (PR) (2006 vs. 2000) estimates. RESULTS: There were 4002 bicyclists observed in 2000 and 5365 in 2006. Overall, HP changed from 75% to 92% among children, 30% to 63% among adolescents and 52% to 55% among adults. Controlling for city, location, companionship, neighborhood age proportion <18, socioeconomic status, and weather conditions, helmet use increased 29% among children (PR = 1.29; 95% CI: 1.20-1.39), over 2-fold among adolescents (PR 2.12; 95% CI: 1.75-2.56), and 14% among adults: (PR = 1.14; CI: 1.02-1.27). CONCLUSIONS: Bicycle helmet legislation was associated with a greater increase in helmet use among the target age group (<18). Though HP increased over 2-fold among adolescents to an estimated 63% in 2006, this percentage was approximately 30% lower than among children <13.