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.
Background Fall-related injuries are a global public health problem, especially in elderly populations. In this study, the effect of an intervention aimed at reducing the risk of falls in the homes of community-dwelling elderly persons was evaluated. The intervention, which involves home hazards reduction by providing a minor home help service, is provided in the majority of Swedish municipalities.
Methods Intention-to-treat effect estimates were derived using quasi-experimental time series intervention (ITS) analysis for immediate effects and a difference-in-discontinuity (RD) design for long term effects, and community-level estimates were pooled using meta-analysis. The outcome measure was the incidence of fall-related hospitalizations in the treatment population, the age of which varied by municipality (≥65 years, ≥67 years, ≥70 years or ≥75 years).
Results We found no statistically significant reductions in injury incidence in the ITS (IRR 1.01 [95% CI: 0.98–1.05]) or RD (IRR 1.00 [95% CI: 0.97–1.03]) analyses. The results are robust to several different model specifications, including segmented panel regression analysis with linear trend change and community fixed effects parameters.
Conclusions It is unclear whether absence of an effect is due to a low efficacy of the home hazards modifications provided, or a result of low utilisation. Additional studies of the effects on other quality of life measures are recommended before conclusions are drawn regarding the cost-effectiveness of the provision of home help services
Background
Fall-related injuries are a global public health problem, especially in elderly populations. The effect of an intervention aimed at reducing the risk of falls in the homes of community-dwelling elderly persons was evaluated. The intervention mainly involves the performance of complicated tasks and hazards assessment by a trained assessor, and has been adopted gradually over the last decade by 191 of 290 Swedish municipalities.
Methods
A quasi-experimental design was used where intention-to-treat effect estimates were derived using panel regression analysis and a regression-discontinuity (RD) design. The outcome measure was the incidence of fall-related hospitalizations in the treatment population, the age of which varied by municipality (≥65 years, ≥67 years, ≥70 years or ≥75 years).
Results
We found no statistically significant reductions in injury incidence in the panel regression (IRR 1.01 [95% CI: 0.98-1.05]) or RD (IRR 1.00 [95% CI: 0.97-1.03]) analyses. The results are robust to several different model specifications, including segmented panel regression analysis with linear trend change and community fixed effects parameters.
Conclusions
It is unclear whether the absence of an effect is due to a low efficacy of the services provided, or a result of low adherence. Additional studies of the effects on other quality of life measures are recommended before conclusions are drawn regarding the cost-effectiveness of the provision of home help service programs.
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.
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.
In 2011, 88% of all unintentional injury fatalities occurred in home and leisure environments in Sweden, while transportation fatalities accounted for 10% and work/school injuries for 2%. The corresponding proportions among non-fatal injuries were 75, 12 and 13%, respectively. However, 83% of the national governmental expenditure on unintentional injury prevention in 2011 was allocated to transportation safety, 7% to home and leisure, and 10% to the work sector including schools. Likewise, around 85% of the governmental research budget aimed for unintentional injury research was allocated to the transportation sector, 9% to home and leisure environments, and 6% to the work and school sector. Our results reveal a striking lack of correspondence between problem profile and governmental countermeasures.
Objectives: This study aimed to investigate the association between sociodemographic factors and residential fire fatalities in Sweden. A majority of fatal fires occur in housing. An understanding of risk factors and risk groups is a must for well-Founded decisions regarding targeted prevention efforts. There is a lack of consideration of the interrelation between sociodemographic factors and fire fatalities and there is a lack of high quality large-Scale studies. Methods: In this matched case-Control study, residential fire fatalities (cases, n=850) (age above 19 years old) were identified in the national register on fatal fires. Four controls per case were randomly matched by gender and age. ORs were calculated to assess the association between different sociodemographic factors with residential fire fatalities using conditional logistic regression. Results: Having low income, receiving social allowance and receiving health-Related early retirement pension were associated with an increased risk of dying in residential fires. The results also show clearly that adults dying in residential fires to a significantly lower extent were living together with a partner, were in work, were highly educated and lived in urban areas. However, contrary to previous research, living in rented apartments appeared not to influence the risk of death. Conclusions: In this study, we show that fatalities due to residential fires in Sweden are associated with some but not all of previously published sociodemographic risk factors. The results provide valuable information that can improve the guiding and targeting of fire mortality prevention strategies 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.