Segmented Linear Regression Models Research Articles

De-escalation and discontinuation strategies in high-risk neutropenic patients: an interrupted time series analyses of antimicrobial consumption and impact on outcome.

Febrile neutropenia (FN) is the main reason for antibiotic prescription in hematology wards where, on the other hand, antibiotic stewardship (AS) is poorly explored. The objectives of the present study were to evaluate (1) the impact of an AS intervention on antibiotic consumption and (2) the applicability and acceptance rate of the intervention and its clinical impact. A persuasive AS intervention based on European Conference on Infection in Leukaemia (ECIL) guidelines for FN was implemented in a high-risk hematology ward in a tertiary referral public university hospital. This included the creation and diffusion of flow charts on de-escalation and discontinuation of antibiotics for FN, and the introduction in the team of a doctor dedicated to the implementation of flow charts and to antibiotic prescription revision. All consecutive patients receiving antibiotics during hospitalization were included. A segmented linear regression model was performed for the evaluation of antibiotic consumption, taking into account 1-year pre-intervention period and 6-month intervention period. Overall, 137 consecutive antibiotic prescriptions were re-evaluated, 100 prescriptions were for FN. A significant reduction of the level of carbapenem consumption was observed during the intervention period (level change (estimate coefficient ± standard error) = - 135.28 ± 59.49; p = 0.04). Applicability and acceptability of flow charts were high. No differences in terms of intensive care unit transfers, bacteremia incidence, and mortality were found. A persuasive AS intervention in hematology significantly reduced carbapenem consumption without affecting outcome and was well accepted. This should encourage further applications of ECIL guidelines for FN.

Association of Medicare's Bundled Payment Reform With Changes in Use of Vitamin D Among Patients Receiving Maintenance Hemodialysis: An Interrupted Time-Series Analysis

Medicare's 2011 prospective payment system (PPS) was introduced to curb overuse of separately billable injectable drugs. After epoietin, intravenous (IV)vitamin D analogues are the biggest drugcost drivers in hemodialysis (HD) patients, but the associationbetween PPS introduction and vitamin D therapy has been scarcely investigated. Interrupted time-series analyses. Adult US HD patients represented in the US Renal Data System between 2008 and2013. PPS implementation. The cumulative dose of IV vitamin D analogues (paricalcitol equivalents) per patient per calendar quarter in prevalent HD patients. The average starting dose of IV vitamin D analogues and quarterly rates of new vitamin D use (initiations/100 person-months) in incident HD patients within 90 days of beginning HD therapy. Segmented linear regression models of the immediate change and slope change over time of vitamin D use after PPS implementation. Among 359,600 prevalent HD patients, IV vitamin D analogues accounted for 99% of the total use, and this trend was unchanged over time. PPS resulted in an immediate 7% decline in the average dose of IV vitamin D analogues (average baseline dose= 186.5 μg per quarter; immediate change=-13.5 μg [P < 0.001]; slope change= 0.43 per quarter [P = 0.3]) and in the starting dose of IVvitamin D analogues in incident HD patients (average baseline starting dose= 5.22 μg; immediate change=-0.40 μg [P<0.001]; slope change=-0.03 per quarter [P= 0.03]). The baseline rate of vitamin D therapy initiation among 99,970 incident HD patients was 44.9/100 person-months and decreased over time, even before PPS implementation (pre-PPS β=-0.46/100 person-months [P < 0.001]; slope change=-0.19/100 person-months [P=0.2]). PPS implementation was associated with an immediate change in initiation levels (by-4.5/100 person-months; P < 0.001). Incident HD patients were restricted to those 65 years or older. PPS implementation was associated with a 7% reduction in the average dose and starting dose of IV vitamin D analogues and a 10% reduction in the rate of vitamin D therapy initiation.

How can General practitioners improve the quality of their care?

New treatments are being developed for myotonic dystrophy type 1 (DM1). To evaluate their efficacy, knowledge about the natural history of respiratory dysfunction and its relationship with the genotype will be crucial. Also needed is information on factors predicting the time-course of respiratory function in DM1. Using data from 283 patients, we built a segmented linear mixed-effects regression model to assess respiratory function changes over time. Respiratory variables associated with the CTG repeat number were identified by multivariate linear regression analysis. Cox proportional-hazards regression was used to estimate hazard ratios (HRs) for starting non-invasive ventilation (NIV). Higher CTG repeat number was associated with peak cough flow impairment (p = 0.007) and with lower values for maximal inspiratory pressure (p <0.0001) and upright vital capacity. A vital capacity decline over time was associated with older age at first evaluation (p <0.0001), higher CTG repeat number (p <0.0001), and higher baseline body mass index (p = 0.0004). NIV initiation was associated with lower peak cough flow (p <0.001) after age and PaCO2 adjustment. Earlier and closer monitoring with routine peak cough flow determination in adults with congenital DM1, combined with weight control, may diminish the risk of respiratory complications and optimise other aspects of management.

Genotype and other determinants of respiratory function in myotonic dystrophy type 1

New treatments are being developed for myotonic dystrophy type 1 (DM1). To evaluate their efficacy, knowledge about the natural history of respiratory dysfunction and its relationship with the genotype will be crucial. Also needed is information on factors predicting the time-course of respiratory function in DM1. Using data from 283 patients, we built a segmented linear mixed-effects regression model to assess respiratory function changes over time. Respiratory variables associated with the CTG repeat number were identified by multivariate linear regression analysis. Cox proportional-hazards regression was used to estimate hazard ratios (HRs) for starting non-invasive ventilation (NIV). Higher CTG repeat number was associated with peak cough flow impairment (p = 0.007) and with lower values for maximal inspiratory pressure (p < 0.0001) and upright vital capacity. A vital capacity decline over time was associated with older age at first evaluation (p < 0.0001), higher CTG repeat number (p < 0.0001), and higher baseline body mass index (p = 0.0004). NIV initiation was associated with lower peak cough flow (p < 0.001) after age and PaCO2 adjustment. Earlier and closer monitoring with routine peak cough flow determination in adults with congenital DM1, combined with weight control, may diminish the risk of respiratory complications and optimise other aspects of management.

Reducing waiting time and raising outpatient satisfaction in Chinese public tertiary hospitals: an interrupted time-series study

BackgroundIt is globally agreed that a well-designed health system delivers timely and convenient access to health services for all patients. Many interventions aiming to reduce waiting times have been implemented in Chinese public tertiary hospitals to improve patients' satisfaction. However, few interventions were well documented, and the effects were rarely measured with robust methods. MethodsWe did a longitudinal study of the length of waiting times in a public tertiary hospital in southern China, which developed comprehensive data collection systems. Data were extracted from the hospital's information systems and patient satisfaction surveys. We analysed longitudinal time-series data using a segmented linear regression model with SPSS 21·0 to assess changes in levels and trends of waiting times before and after the introduction of waiting time reduction interventions. Pearson correlation analysis was done to indicate the strength of association between waiting times and patient satisfactions. The statistical significance level was set at 0·05. FindingsThe monthly average length of waiting time decreased by 3·49 min (p=0·003) for consultations and by 8·70 min (p=0·02) for filling prescriptions in the corresponding month in which respective interventions were introduced. The trend shifted from baseline from a slight increase to a significant decrease in time for filling prescriptions (p=0·003). We found a significant negative correlation between waiting time of filling prescriptions and outpatient satisfaction towards pharmacy services (r=–0·71; p=0·004). InterpretationThe interventions aimed at reducing waiting time and raising patient satisfaction in Fujian Provincial Hospital are effective. A long-lasting reduction on waiting time for filling prescriptions was observed because of carefully designed continuous efforts, rather than a one-time campaign, and with appropriate incentives implemented by a taskforce authorised by the hospital managers. This case provides a model of continuous quality improvement and optimisation of management process with the support of relevant evidence. FundingNational Health and Family Planning Commission of China.

Reducing waiting time and raising outpatient satisfaction in a Chinese public tertiary general hospital-an interrupted time series study

BackgroundIt is globally agreed that a well-designed health system deliver timely and convenient access to health services for all patients. Many interventions aiming to reduce waiting times have been implemented in Chinese public tertiary hospitals to improve patients’ satisfaction. However, few were well-documented, and the effects were rarely measured with robust methods.MethodsWe conducted a longitudinal study of the length of waiting times in a public tertiary hospital in Southern China which developed comprehensive data collection systems. Around an average of 60,000 outpatients and 70,000 prescribed outpatients per month were targeted for the study during Oct 2014-February 2017. We analyzed longitudinal time series data using a segmented linear regression model to assess changes in levels and trends of waiting times before and after the introduction of waiting time reduction interventions. Pearson correlation analysis was conducted to indicate the strength of association between waiting times and patient satisfactions. The statistical significance level was set at 0.05.ResultsThe monthly average length of waiting time decreased 3.49 min (P = 0.003) for consultations and 8.70 min (P = 0.02) for filling prescriptions in the corresponding month when respective interventions were introduced. The trend shifted from baseline slight increasing to afterwards significant decreasing for filling prescriptions (P =0.003). There was a significant negative correlation between waiting time of filling prescriptions and outpatient satisfaction towards pharmacy services (r = −0.71, P = 0.004).ConclusionsThe interventions aimed at reducing waiting time and raising patient satisfaction in Fujian Provincial Hospital are effective. A long-lasting reduction effect on waiting time for filling prescriptions was observed because of carefully designed continuous efforts, rather than a one-time campaign, and with appropriate incentives implemented by a taskforce authorized by the hospital managers. This case provides a model of carrying out continuous quality improvement and optimizing management process with the support of relevant evidence.

Total Body Adiposity And Accumulated Visceral Adipose Tissue

PURPOSE: It has been shown that visceral adipose tissue (VAT) does not increase linearly with an increase in total body fat percentage (BF%). Instead, a BF% threshold was identified above which VAT increases more rapidly. The primary purpose of this study was to investigate the effect of age, ethnicity, and sex on the BF% threshold at which the accumulation of VAT increases significantly. METHODS: A convenience sample of 3,211 (1,756 females and 1,455 males) participants, 18-75 years of age, who had a dual X-ray absorptiometry scan conducted at The Fitness Institute of Texas between 2008-2016, were included in this study. Self-selected ethnicities were Asian (18.1%), Black (6.7%), Hispanic (19.8%) and White (55.4%). A set of segmented linear regression models for each sex and ethnicity category were specified to estimate thresholds at which the relationship between BF% and VAT mass changed. RESULTS: The BF% threshold above which VAT increased more rapidly was identified and it varied between females and males and among ethnicities. The BF% threshold for females were: Asian 29.2%, Black 35.6%, Hispanic 31.7%, and White 34.2%. For males, the BF% thresholds were: Asian 25.3%, Black 23.9%%, Hispanic 24.3%, and White 22.8%. There was more variability in VAT mass among participants above the BF% threshold than for those below. In order to attempt to explain this additional variability, age and ethnicity were added as covariates in multiple linear regression models applied to post-threshold participants, for both females and males separately. Post-threshold, the impact of BF% is amplified for older participants controlling for ethnicity for both females (β = 0.28, SE = .003, p < .001) and males (β = 0.81, SE = .006, p < .001), meaning that the VAT increased at a faster rate for older individuals. Controlling for age, BF% has a significantly lower impact on VAT mass for Black females compared to their White counterparts (β = -3.05, SE = 1.44, p < .05) and Asian males compared to their White counterparts (β = -0.11, SE = 2.3, p < .001), meaning that the VAT increased at a faster rate for White females and males than Black females and Asian males. CONCLUSION: The BF% threshold above which VAT increased more rapidly was identified and it varied by sex and ethnicity. Post threshold the increase in VAT was affected by age and ethnicity.

Do active case-finding projects increase the number of tuberculosis cases notified at national level?

To analyse the impact of active tuberculosis case finding (ACF) projects on the number of sputum smear-positive (SS+) tuberculosis (TB) cases notified at national level. Case-finding results of the 16 countries that participated in the first wave of the TB REACH project were analysed. Information on the number of SS+ TB cases at national level were taken from the 2014 World Health Organization global tuberculosis report. A segmented linear regression model was used to analyse trends in notification. An increase in SS+ TB cases from 3% to 334% was observed in the areas of intervention of the TB REACH project in almost all countries. There were no significant increases in the number of SS+ TB cases notified at the national level in most countries, except in two countries during the intervention period (Benin and Kenya), and in one country after the intervention period (Somalia). The TB REACH project had no impact on SS+ TB cases notified at national level in almost all countries during and after the intervention. ACF projects are pilot studies that are often difficult to reproduce at national level due to their high cost and the lack of human resources.

Evaluation of energy consumption during aerobic sewage sludge treatment in dairy wastewater treatment plant

The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm−3 with the average value at 1.17 kWhm−3. The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs.

Crystalline methamphetamine use and methamphetamine-related harms in Australia.

Concerns about crystal methamphetamine use and harm have increased in multiple countries. This paper describes how changes in the availability and use of crystal methamphetamine have impacted on methamphetamine-related harms in Australia. Data on methamphetamine use were obtained from population-level surveys, health service data and surveys of drug use among sentinel groups of ecstasy users and people who inject drugs. Data were obtained on seizures, arrests, clandestine laboratory detections, hospital separations, mental health unit admissions, drug telephone helpline calls and drug treatment episodes. Segmented linear regression models were fitted to identify changes in these series using log-transformed data where appropriate. The availability of crystal methamphetamine has increased as evidenced by increased laboratory detections, domestic seizures and purity of the seized drug. Population surveys do not report an increase in the number of people who used at least once in the past year. However, more users report using crystal methamphetamine rather than lower-purity powder methamphetamine and more regular use. Indicators of methamphetamine-related harms have increased in parallel with this change. Amphetamine-related helpline calls, drug treatment, arrests and hospital admissions for amphetamine disorders and psychosis all peaked in the mid-2000s, declined for several years and have increased steeply since 2010. The increased availability and use of crystal methamphetamine have been associated with increased regular use and harms. Treatment is required for those experiencing problems and the capacity of health services to provide care needs to be enhanced.[Degenhardt L, Sara G, Connor JP, McKetin R, Roxburgh A, Dobbins T, Farrell M, Burns L, Hall WD. Crystalline methamphetamine use and methamphetamine-related harms in Australia. Drug Alcohol Rev 2017;36:160-170].

Critical care transition programs and the risk of readmission or death after discharge from ICU.

Critical care transition programs have been widely implemented to improve the safety of patient discharge from ICU, but have undergone limited evaluation. We sought to evaluate implementation of a critical care transition program on patient readmission to ICU (72 h) and mortality (14 days). Interrupted time series analysis of 32,234 consecutive adult patients discharged alive from medical-surgical ICUs in eight hospitals in two cities between January 1, 2002 and January 1, 2012. A multidisciplinary ICU provider team (physician, nurse, respiratory therapist) that serially evaluated each patient after ICU discharge was implemented in three hospitals in one city (study group), but not the five hospitals in the other city (control group). Temporal changes were examined using multivariable, segmented linear regression models. After implementation of the program, there was an immediate non-significant decrease in the absolute proportion of patients readmitted to ICU in the study group (-0.4%, 95% CI -1.7 to +1.0%) and a non-significant increase in the absolute proportion of patients readmitted to ICU in the control group (+1.0%, 95% CI -0.3 to +2.2%). Subsequently, there were non-significant changes in the absolute proportion of patients readmitted to ICU in both the study (+0.1% per quarter; 95% CI, -0.1 to +0.2%) and control (-0.1 per quarter; 95% CI, -0.2 to +0.1%) groups over time. No significant changes were observed in mortality. The results were stable across patient subgroups. Implementation of a critical care transition program was not associated with patient readmission to ICU or mortality.

Increased trend in extracorporeal membrane oxygenation use by adults in the United States since 2007.

BackgroundExtracorporeal membrane oxygenation (ECMO) has been increasingly studied as a life support modality, but it is unclear if its use has changed over time. Recent publication shows no significant trend in use of ECMO over time; however, this report does not include more recent data. We performed trend analysis to determine if and when the use of ECMO changed in the past decade.ResultsWe identified hospitalizations (2000–2011) in the Nationwide Inpatient Sample during which ECMO was recorded. We used a segmented linear regression model to determine trend and to identify a temporal change point when rate of ECMO use increased. ECMO use gradually grew until 2007, at which time there was a dramatic increase in the rate (p = 0.0003). There was no difference in mortality after 2007 (p = 0.3374), but there was longer length of stay (p = 0.0001) and smaller percentage of women (p = 0.005).ConclusionsThere has been a marked increase in ECMO use since 2007. As ECMO use becomes more common, further study regarding indications, cost-effectiveness, and outcomes is warranted to guide optimal use.

Ozone exposure and flux-based response functions for photosynthetic traits in wheat, maize and poplar

Ozone exposure- and dose-response relationships based on photosynthetic leaf traits (CO2 assimilation, chlorophyll content, Rubisco and PEPc activities) were established for wheat, maize and poplar plants grown in identical controlled conditions, providing a comparison between crop and tree species, as well as between C3 and C4 plants. Intra-specific variability was addressed by comparing two wheat cultivars with contrasting ozone tolerance. Depending on plant models and ozone levels, first-order, second-order and segmented linear regression models were used to derive ozone response functions. Overall, flux-based functions appeared superior to exposure-based functions in describing the data, but the improvement remained modest. The best fit was obtained using the POD0.5 for maize and POD3 for poplar. The POD6 appeared relevant for wheat, although intervarietal differences were found. Our results suggest that taking into account the dynamics of leaf antioxidant capacity could improve current methods for ozone risk assessment for plants.

Effect of Restricting Access to Health Care on Health Expenditures among Asylum-Seekers and Refugees: A Quasi-Experimental Study in Germany, 1994-2013.

BackgroundAccess to health care for asylum-seekers and refugees (AS&R) in Germany is initially restricted before regular access is granted, allegedly leading to delayed care and increasing costs of care. We analyse the effects of (a) restricted access; and (b) two major policy reforms (1997, 2007) on incident health expenditures for AS&R in 1994-2013.Methods and FindingsWe used annual, nation-wide, aggregate data of the German Federal Statistics Office (1994-2013) to compare incident health expenditures among AS&R with restricted access (exposed) to AS&R with regular access (unexposed). We calculated incidence rate differences (∆IRt) and rate ratios (IRRt), as well as attributable fractions among the exposed (AFe) and the total population (AFp). The effects of between-group differences in need, and of policy reforms, on differences in per capita expenditures were assessed in (segmented) linear regression models. The exposed and unexposed groups comprised 4.16 and 1.53 million person-years. Per capita expenditures (1994–2013) were higher in the group with restricted access in absolute (∆IRt = 375.80 Euros [375.77; 375.89]) and relative terms (IRR = 1.39). The AFe was 28.07% and the AFp 22.21%. Between-group differences in mean age and in the type of accommodation were the main independent predictors of between-group expenditure differences. Need variables explained 50-75% of the variation in between-group differences over time. The 1997 policy reform significantly increased ∆IRt adjusted for secular trends and between-group differences in age (by 600.0 Euros [212.6; 986.2]) and sex (by 867.0 Euros [390.9; 1342.5]). The 2007 policy reform had no such effect.ConclusionThe cost of excluding AS&R from health care appears ultimately higher than granting regular access to care. Excess expenditures attributable to the restriction were substantial and could not be completely explained by differences in need. An evidence-informed discourse on access to health care for AS&R in Germany is needed; it urgently requires high-quality, individual-level data.

How Did Multiple FDA Actions Affect the Utilization and Reimbursed Costs of Thiazolidinediones in US Medicaid?

PurposeThe US Food and Drug Administration (FDA) communicated the potential cardiovascular risk of thiazolidinediones (rosiglitazone and pioglitazone) in 2007 and required a Risk Evaluation and Mitigation Strategy (REMS) for rosiglitazone in 2010. It also communicated in 2010 the potential risk of bladder cancer with pioglitazone use. This study examined the effects of these multiple FDA actions on utilization and reimbursed costs of thiazolidinediones in state Medicaid programs. MethodsState Drug Utilization Data from the Centers for Medicare & Medicaid Services were assessed. An interrupted time series design and segmented linear regression models were used to examine changes in market shares according to both prescription volume and reimbursed costs for rosiglitazone and pioglitazone in the Northeast and Midwest regions of the United States after multiple FDA actions. FindingsCompared with expected rates, there were relative reductions of 65.84% (Northeast region) and 55.09% (Midwest region) in the use of rosiglitazone at 1 year after the 2007 FDA actions for thiazolidinediones and cardiac risk. At the same time, relative increases of 7.30% and 9.28% in the use of pioglitazone were observed in the Northeast and Midwest regions, respectively. Changes in both use and costs of rosiglitazone after the 2010 REMS program could not be estimated because of the already low rates (~1%) before REMS was implemented. One year after the 2010 FDA actions for pioglitazone and its possible association with bladder cancer, relative reductions in pioglitazone use of 21.41% (Northeast region) and 18.12% (Midwest region) were detected. ImplicationsThe Northeast and Midwest regions reported similar patterns of changes after the FDA actions. Use and costs of rosiglitazone were substantially reduced after the 2007 FDA actions for cardiovascular risk, and this drug was rarely used after the 2010 REMS program. Conversely, use and costs of pioglitazone were substantially reduced after the 2010 FDA actions regarding the drug’s possible risk of bladder cancer.

Blood flow vortices along the main pulmonary artery measured with MR imaging for diagnosis of pulmonary hypertension.

To approximate the functional relationship between invasively measured mean pulmonary arterial pressure (mPAP) and the phase-contrast magnetic resonance (MR) imaging-derived duration of vortical blood flow along the main pulmonary artery and to analyze its applicability for noninvasive diagnosis of pulmonary hypertension (PH) and borderline mPAP. The local ethics review board approved this prospective study of 145 patients suspected of having PH (69 patients with PH, 19 patients with borderline mPAP, and 57 patients with normal mPAP) who underwent right heart catheterization (RHC) and three-directional phase-contrast MR imaging of the main pulmonary artery. Velocity fields were viewed with dedicated software and evaluated for the duration of vortical blood flow in the main pulmonary artery (tvortex, the percentage of cardiac phases with vortex present). The relationship between mPAP at RHC and tvortex was assessed by means of a segmented linear regression model, and by Bland-Altman and receiver operating characteristic curve analyses. The relationship between mPAP and tvortex was described adequately (R(2) = 0.95) as linearly increasing, from tvortex of 0% (mPAP ≤ 16.0 mm Hg) with a slope of 1.59% per millimeter of mercury. The standard deviation between mPAP values derived from RHC and those estimated by using tvortex was 3.9 mm Hg. The area under the curve for tvortex-based diagnosis of PH was 0.994 (95% confidence interval [CI]: 0.982, 0.998), and the calculated PH cut-off value (tvortex ≥ 14.3%) resulted in sensitivity of 0.97 (95% CI: 0.90, 0.99) and specificity of 0.96 (95% CI: 0.89, 0.99). Vortical blood flow with tvortex less than 14.3% was specific for borderline mPAP. Duration of vortical blood flow in the main pulmonary artery that is determined by using phase-contrast MR imaging allows accurate estimation of elevated mPAP and diagnosis of PH. Clinical trial registration no. NCT00575692.

The Impact of Cost Containment Reforms to the Pharmaceutical Benefits Scheme (Pbs) On Prescribing Volumes And Expenditure In Australia: 1992 To 2011.

Objectives: To investigate the impact of cost containment measures on PBS prescribing volumes and expenditure. Methods: Segmented linear regression models were used to analyse the time series data from Medicare Australia’s PBS Statistics. Seven measures and four new listing dates of statins were investigated. Results: Many of the cost containment measures were effective in containing costs. Conclusions: The safety net 20 days rule was estimated to be the most effective in reducing drugs utilisation and expenditure.

FRI0564-HPR Aquatic Exercise Brings Relief to Patients with Inflammatory Rheumatic Diseases

BackgroundAquatic exercises, the performance of structured exercises while the body is immersed in heated water, are frequently used as an adjunct therapeutic modality for patients with rheumatic diseases. Updated evidence...

Effectiveness of an improved road safety policy in Ethiopia: an interrupted time series study.

BackgroundIn recent years, there has been an increasing interest in implementing road safety policy by different low income countries. However; the evidence is scarce on its success in the reduction of crashes, injuries and deaths. This study was conducted to assess whether road crashes, injuries and fatalities was reduced following the road safety regulation introduced as of September 2007 by Oromia Regional State Transport Bureau.MethodsRoutine road traffic accident data for the year 2002-2011were collected from sixteen traffic police offices. Data on average daily vehicle flow was obtained from the Ethiopian Road Authority. Interrupted time series design using segmented linear regression model was applied to estimate the effect of an improved road safety policy.ResultsA total of 4,053 crashes occurred on Addis Ababa - Adama/Hawassa main road. Of these crashes, almost half 46.4% (1,880) were property damage, 29.4% (1,193) were fatal and 24.2% (980) injury crashes, resulting 1,392 fatalities and 1,749 injuries. There were statistically significant reductions in non-injury crashes and deaths. Non-injury crash was reduced by 19% and fatality by 12.4% in the first year of implementing the revised transport safety regulation.ConclusionAlthough revised road safety policy helped in reducing motor vehicle crashes and associated fatalities, the overall incidence rate is still very high. Further action is required to avoid unnecessary loss of lives.

Changes in Memory before and after Stroke Differ by Age and Sex, but Not by Race

Background: Post-stroke memory impairment is more common among older adults, women and blacks. It is unclear whether post-stroke differences reflect differential effects of stroke per se or differences in prestroke functioning. We compare memory trajectories before and after stroke by age, sex and race. Methods: Health and Retirement Study participants aged ≥50 years (n = 17,341), with no stroke history at baseline, were interviewed biennially up to 10 years for first self- or proxy-reported stroke (n = 1,574). Segmented linear regression models were used to compare annual rates of memory change before and after stroke among 1,169 stroke survivors, 405 stroke decedents and 15,767 stroke-free participants. Effect modification was evaluated with analyses stratified by baseline age (≤70 vs. >70), sex and race (white vs. nonwhite), and using interaction terms between age/sex/race indicators and annual memory change. Results: Older (>70 years) adults experienced a faster memory decline before stroke (-0.19 vs. -0.10 points/year for survivors, -0.24 vs. -0.13 points/year for decedents, p < 0.001 for both interactions), and among stroke survivors, larger memory decrements (-0.64 vs. -0.26 points, p < 0.001) at stroke and faster memory decline (-0.15 vs. -0.07 points/year, p = 0.003) after stroke onset, compared to younger adults. Female stroke survivors experienced a faster prestroke memory decline than male stroke survivors (-0.14 vs. -0.10 points/year, p < 0.001). However, no sex differences were seen for other contrasts. Although whites had higher post-stroke memory scores than nonwhites, race was not associated with rate of memory decline during any period of time; i.e. race did not significantly modify the rate of decline before or after stroke or the immediate effect of stroke on memory. Conclusions: Older age predicted worse memory change before, at and after stroke onset. Sex and race differences in post-stroke memory outcomes might be attributable to prestroke disparities, which may be unrelated to cerebrovascular disease.