Carl Bonander

Investigating the fall-injury reducing effect of impact absorbing flooring among female nursing home residents: initial results

Background Fall-related injuries affect the lives of elderly to a substantial degree. This quasi-experimental study investigates the fall-injury reducing effect of impact absorbing flooring among female nursing home residents. Methods The intervention site is a nursing home in Sweden where impact absorbing flooring was installed in parts of one of six wards (six out of 10 apartments (excluding bathrooms), the communal dining-room and parts of the corridor). The impact absorbing flooring is a 12 mm thick closed cell flexible polyurethane/polyurea composite tile (500×500 mm) with an exterior surface of polyurethane/polyurea. A generalised linear model (log-binomial) was used to calculate the RR of injury from falls on impact absorbing flooring compared to falls on regular flooring, adjusted for age, body mass index, visual and cognitive impairments. Results During the study period (1 October 2011 to 31 March 2014), 254 falls occurred on regular flooring and 77 falls on impact absorbing flooring. The injury/fall rate was 30.3% for falls on regular flooring and 16.9% for falls on impact absorbing flooring. Adjusted for covariates, the impact absorbing flooring significantly reduced the RR of injury in the event of a fall by 59% (RR 0.41 (95% Cl 0.20 to 0.80)). Conclusions This is, to our knowledge, the first study evaluating the injury-reducing effect of impact absorbing flooring in a nursing home showing statistically significant effect. The results from this study are promising, indicating the considerable potential of impact absorbing flooring as a fall-related injury intervention among frail elderly.

The Effect of the Swedish Bicycle Helmet Law for Children: An Interrupted Time Series Study

BACKGROUND Previous population-based research has shown that bicycle helmet laws can reduce head injury rates among cyclists. According to deterrence theory, such laws are mainly effective if there is a high likelihood of being apprehended. In this study, we investigated the effect of the Swedish helmet law for children under the age of 15, a population that cannot be fined. METHOD An interrupted time series design was used. Monthly inpatient data on injured cyclists from 1998-2012, stratified by age (0-14, 15+), sex, and injury diagnosis, was obtained from the National Patient Register. The main outcome measure was the proportion of head injury admissions per month. Intervention effect estimates were obtained using generalized autoregressive moving average (GARMA) models. Pre-legislation trend and seasonality was adjusted for, and differences-in-differences estimation was obtained using adults as a non-equivalent control group. RESULTS There was a statistically significant intervention effect among male children, where the proportion of head injuries dropped by 7.8 percentage points. There was no evidence of an intervention effect on the proportion of head injuries among female children. CONCLUSION According to hospital admission data, the bicycle helmet law appears to have had an effect only on male children. PRACTICAL APPLICATIONS This study, while quasi-experimental and thus not strictly generalizable, can contribute to increased knowledge regarding the effects of bicycle helmet laws.

The effect of the transition from the ninth to the tenth revision of the International Classification of Diseases on external cause registration of injury morbidity in Sweden

Background Revisions of the International Classification of Diseases (ICD) have previously been shown to cause dramatic effects with regard to injury mortality data when implemented. However, limited knowledge exists on the effects on the coding of external causes of injury morbidity, despite this being an important aspect with regard to injury prevention. Method Hospitalised injuries in Sweden were studied using time series intervention analysis to observe the effect of the ICD change from ICD-9 to ICD-10 in 1997 on external cause coding. Results The results would suggest considerable coding issues with a large spike in the proportion of injury admissions registered without an external cause code in 1997, with continuing, although gradually diminishing, problems up to 2002. The coding change seems to have had an immediate effect on all external cause of injury categories, although the categories that were not directly convertible from ICD-9 to ICD-10 were seemingly more greatly affected. Discussion The study illustrates the potential issues associated with changes between ICD revisions and the importance of data quality control both during surveillance and collection of data, but also when presenting injury trends across ICD versions.

Injury risks in schoolchildren with attention-deficit/hyperactivity or autism spectrum disorder: Results from two school-based health surveys of 6- to 17-year-old children in Sweden

INTRODUCTION Injuries are one of the leading causes of death and disability among children in Sweden and attention-deficit/hyperactivity disorder (ADHD) has previously been associated with an increased risk of injury in pediatric populations elsewhere in the world. Current evidence regarding the possible link between autism spectrum disorder (ASD) and injury risk appears limited, even though some potentially risk-increasing symptoms overlap. The purpose of this study was thus to study the association between both ADHD and ASD concerning the risk of injury among Swedish schoolchildren. METHODS Two samples were used: a population-based register study containing data from 18,416 children ranging from the ages of 6-17years collected by school nurses during 2012/2014 (Survey A), and a national cross-sectional study of 3202 ninth-grade children (~15years old) collected from 92 schools in 2011 (Survey B). The data were analyzed using χ(2)-tests and log-binomial generalized linear models to obtain risk ratios (RR), comparing cases reportedly affected by ADHD or ASD to unaffected controls. RESULTS After adjusting for confounders, ADHD was associated with a 65% increased risk of injury (RR 1.65 [95% CI: 1.32-2.05] in Survey A, and a 57% increased risk of injury (RR 1.57 [95% CI: 1.27-1.95]) in Survey B. ASD was not significantly associated with any differences in injury risk (RR 0.81 [95% CI: 0.57-1.14]). CONCLUSIONS The results indicate that there is an elevated injury risk among Swedish schoolchildren with ADHD but not for children with ASD. Future studies should focus on causal mechanisms mediating the association between ADHD and injuries in order to facilitate injury prevention strategies. PRACTICAL APPLICATIONS Parents and teachers of schoolchildren with ADHD should be made aware of the elevated injury risks associated with the diagnosis. Safety experts and injury control professionals should consider the development of specialized prevention strategies in order to reduce these risks.

Investigating the effect of banning non-reduced ignition propensity cigarettes on fatal residential fires in Sweden

BACKGROUND Annually, 100 people die as a result of residential fires in Sweden and almost a third of the fatal fires are known to be caused by smoking. In an attempt to reduce the occurrence of these events, reduced ignition propensity (RIP) cigarettes have been developed. They are designed to reduce the risk of fire by preventing the cigarette from burning through the full length when left unattended. In November 2011, a ban was introduced, forbidding the production and sale of all non-RIP cigarettes in all member states of the European Union, including Sweden. METHODS Monthly data on all recorded residential fires and associated fatalities in Sweden from January 2000 to December 2013 were analyzed using an interrupted time series design. The effect of the intervention [in relative risk (RR)] was quantified using generalised additive models for location, shape and scale. RESULTS There were no statistically significant intervention effects on residential fires (RR 0.95 [95% CI: 0.89-1.01]), fatal residential fires (RR 0.99 [95% CI: 0.80-1.23]), residential fires where smoking was a known cause (RR 1.10 [95% CI: 0.95-1.28]) or fatal residential fires where smoking was a known cause (RR 0.92 [95% CI: 0.63-1.35]). CONCLUSION No evidence of an effect of the ban on all non-RIP cigarettes on the risk of residential fires in Sweden was found. The results may not be generalisable to other countries.

Compared with what? Estimating the effects of injury prevention policies using the synthetic control method

Introduction This paper discusses the application of the synthetic control method to injury-related interventions using aggregate data from public information systems. The method selects and determines the optimal control unit in the data by minimising the difference between the pre-intervention outcomes in one treated unit (eg, a state) and a weighted combination of potential control units. Method I demonstrate the synthetic control method by an application to Florida’s post-2010 policy and law enforcement initiatives aimed at bringing down opioid overdose deaths. Using opioid-related mortality data for a panel of 46 states observed from 1999 to 2015, the analysis suggests that a weighted combination of Maine (46.1%), Pennsylvania (34.4%), Nevada (5.4%), Washington (5.3%), West Virginia (4.3%) and Oklahoma (3.4%) best predicts the preintervention trajectory of opioid-related deaths in Florida between 1999 and 2009. Model specification and placebo tests, as well as an iterative leave-k-out sensitivity analysis are used as falsification tests. Results The results indicate that the policies have decreased the incidence of opioid-related deaths in Florida by roughly 40% (or −6.19 deaths per 100.000 person-years) by 2015 compared with the evolution projected by the synthetic control unit. Sensitivity analyses yield an average estimate of −4.55 deaths per 100.000 person-years (2.5th percentile: −1.24, 97.5th percentile: −7.92). The estimated cumulative effect in terms of deaths prevented in the postperiod is 3705 (2.5th percentile: 1302, 97.5th percentile: 6412). Discussion Recommendations for practice, future research and potential pitfalls, especially concerning low-count data, are discussed. Replication codes for Stata are provided.

The state of the residential fire fatality problem in Sweden: Epidemiology, risk factors, and event typologies

INTRODUCTION Residential fires represent the largest category of fatal fires in Sweden. The purpose of this study was to describe the epidemiology of fatal residential fires in Sweden and to identify clusters of events. METHOD Data was collected from a database that combines information on fatal fires with data from forensic examinations and the Swedish Cause of Death-register. Mortality rates were calculated for different strata using population statistics and rescue service turnout reports. Cluster analysis was performed using multiple correspondence analysis with agglomerative hierarchical clustering. RESULTS Male sex, old age, smoking, and alcohol were identified as risk factors, and the most common primary injury diagnosis was exposure to toxic gases. Compared to non-fatal fires, fatal residential fires more often originated in the bedroom, were more often caused by smoking, and were more likely to occur at night. Six clusters were identified. The first two clusters were both smoking-related, but were separated into (1) fatalities that often involved elderly people, usually female, whose clothes were ignited (17% of the sample), (2) middle-aged (45-64years old), (often) intoxicated men, where the fire usually originated in furniture (30%). Other clusters that were identified in the analysis were related to (3) fires caused by technical fault, started in electrical installations in single houses (13%), (4) cooking appliances left on (8%), (5) events with unknown cause, room and object of origin (25%), and (6) deliberately set fires (7%). CONCLUSIONS Fatal residential fires were unevenly distributed in the Swedish population. To further reduce the incidence of fire mortality, specialized prevention efforts that focus on the different needs of each cluster are required. PRACTICAL APPLICATIONS Cooperation between various societal functions, e.g. rescue services, elderly care, psychiatric clinics and other social services, with an application of both human and technological interventions, should reduce residential fire mortality in Sweden.

A quasi-experimental evaluation of compliant flooring in a residential care setting

Background Fall injuries affect the lives of older people to a substantial degree. This quasi-experimental observational study investigates the potential fall injury reducing effect of a compliant flooring in a residential care setting. Methods The allocation of the compliant flooring was non-random. Data on fall-events and individual characteristics were collected in a residential care unit during a period of 68 months. The primary outcome was the fall injury rate per fall, and a logistic regression analysis was used to test for the effect of complaint flooring. Falls per 1000 bed days was the secondary outcome, used to measure the difference in fall risk on compliant flooring versus regular flooring. Results The event dataset is an unbalanced panel with repeated observations on 114 individuals, with 70% women. The mean age was 84.9 years of age, the average Body Mass Index (BMI) was 24.7, and there was a mean of 6.57 (SD: 15.28) falls per individual. The unadjusted effect estimate showed a non-significant relative risk injury reduction of 29% per fall (RR 0.71 [95% CI: 0.46–1.09]) compared to regular flooring. Re-estimating, excluding identified outliers, showed an injury risk reduction of 63% (RR 0.37 [95% CI: 0.25–0.54]). Falls per 1000 bed days showed that individuals living in apartments with compliant flooring had a fall rate of 5.3 per 1000 bed days compared to a fall rate of 8.4 per 1000 bed days among individuals living in regular apartments. This corresponds to an incidence rate ratio (IRR) of 0.63 (95% exact Poisson CI: 0.50–0.80). Conclusion The results of this non-randomized study indicate that compliant flooring has the potential to reduce the risk of fall injury without increasing the fall risk among older people in a Swedish residential care setting.

Are fire safe cigarettes actually fire safe? Evidence from changes in US state laws

Objective To estimate the effects of fire safe cigarette laws on fire mortality and cigarette-related fires in the USA. Methods We examined the gradual implementation of the laws to identify their average effects, using difference-in-differences analysis to account for common year effects, time-invariant state effects, state-specific trends and observable time-varying state-level covariates. Results We found no statistically significant effects on all-cause fire mortality, residential fire mortality or cigarette-caused fire rates. The estimates for cigarette-caused fire deaths were significant under some specifications, but were not robust to the inclusion of state-specific trends or comparisons to effects on other cause-determined fires. Conclusions Given the mixed state of our results, we conclude that previous claims regarding the effects of fire safe cigarette laws may be premature.

From loss of life to loss of years: a different view on the burden of injury fatalities in Sweden 1972–2014

Background Worldwide, about 5.8 million people die each year due to injuries. In Sweden, the corresponding number amounts to 3000. There are large differences among injury types regarding the age-profile of the fatalities and as most of them occur in older age groups, counting the absolute number of injury fatalities does not fully reflect the size of the burden of injury. Methods Using age- and sex-specific life expectancy tables in combination with data on external causes of injury, the number of injury fatalities in Sweden for the time period 1972-2014 is converted to a sum of potential years of life lost (PYLL). We then fit cause and group-specific spline regression models to the data to estimate temporal trends in both fatality counts and PYLL. Results There has been a steady reduction in the number of injury fatalities and in the sum of PYLL from the early 1970s to around the year 2000. Since then, there has been an increase in the number of injury fatalities and in the sum of PYLL. The upward trend is mainly explained by an increasing number of deaths due to poisonings and suicide, specifically among younger men. Conclusions The increases in suicide and poisoning mortality offset the reductions in downward trending causes of injury mortality during the last decades. The share of PYLL is larger than the share of fatalities for both suicides and poisonings implying that an aging population does not cause the increase.