Scott R. Walter

The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia

The study aimed to assess the effect of compulsory cycle helmet legislation on cyclist head injuries given the ongoing debate in Australia as to the efficacy of this measure at a population level. We used hospital admissions data from New South Wales, Australia, from a 36 month period centred at the time legislation came into effect. Negative binomial regression of hospital admission counts of head and limb injuries to cyclists were performed to identify differential changes in head and limb injury rates at the time of legislation. Interaction terms were included to allow different trends between injury types and pre- and post-law time periods. To avoid the issue of lack of cyclist exposure data, we assumed equal exposures between head and limb injuries which allowed an arbitrary proxy exposure to be used in the model. As a comparison, analyses were also performed for pedestrian data to identify which of the observed effects were specific to cyclists. In general, the models identified a decreasing trend in injury rates prior to legislation, an increasing trend thereafter and a drop in rates at the time legislation was enacted, all of which were thought to represent background effects in transport safety. Head injury rates decreased significantly more than limb injury rates at the time of legislation among cyclists but not among pedestrians. This additional benefit was attributed to compulsory helmet legislation. Despite numerous data limitations, we identified evidence of a positive effect of compulsory cycle helmet legislation on cyclist head injuries at a population level such that repealing the law cannot be justified.

The Effect of Computerized Provider Order Entry Systems on Clinical Care and Work Processes in Emergency Departments: A Systematic Review of the Quantitative Literature

STUDY OBJECTIVE We undertake a systematic review of the quantitative literature related to the effect of computerized provider order entry systems in the emergency department (ED). METHODS We searched MEDLINE, EMBASE, Inspec, CINAHL, and CPOE.org for English-language studies published between January 1990 and May 2011. RESULTS We identified 1,063 articles, of which 22 met our inclusion criteria. Sixteen used a pre/post design; 2 were randomized controlled trials. Twelve studies reported outcomes related to patient flow/clinical work, 7 examined decision support systems, and 6 reported effects on patient safety. There were no studies that measured decision support systems and its effect on patient flow/clinical work. Computerized provider order entry was associated with an increase in time spent on computers (up to 16.2% for nurses and 11.3% for physicians), with no significant change in time spent on patient care. Computerized provider order entry with decision support systems was related to significant decreases in prescribing errors (ranging from 17 to 201 errors per 100 orders), potential adverse drug events (0.9 per 100 orders), and prescribing of excessive dosages (31% decrease for a targeted set of renal disease medications). CONCLUSION There are tangible benefits associated with computerized provider order entry/decision support systems in the ED environment. Nevertheless, when considered as part of a framework of technical, clinical, and organizational components of the ED, the evidence base is neither consistent nor comprehensive. Multimethod research approaches (including qualitative research) can contribute to understanding of the multiple dimensions of ED care delivery, not as separate entities but as essential components of a highly integrated system of care.

Managing competing demands through task-switching and multitasking: a multi-setting observational study of 200 clinicians over 1000 hours

Objective To provide a detailed characterisation of clinicians’ work management strategies. Design 1002.3 h of observational data were derived from three previous studies conducted in a teaching hospital in Sydney, Australia, among emergency department (ED) doctors (n=40), ward doctors (n=57) and ward nurses (n=104). The rates of task-switching (pausing a task to handle an incoming task) and multitasking (adding a task in parallel to an existing task) were compared in each group. Random intercepts logistic regression was used to determine factors significantly associated with clinicians’ use of task-switching over multitasking and to quantify variation between individual clinicians. Results Task-switching rates were higher among ED doctors (6.0 per hour) than ward staff (2.2 and 1.8 per hour for doctors and nurses, respectively) and vice versa for multitasking rates (9.2 vs 17.3 and 14.1 per hour). Clinicians’ strategy use was significantly related to the nature and complexity of work and to the person they were working with. In some settings, time of day, day of the week or previous chosen strategy affected a clinicians strategy. Independent of these factors, there was significant variation between individual clinicians in their use of strategies in a given situation (ED doctors p=0.04, ward staff p=0.03). Conclusions Despite differences in factors associated with work management strategy use among ED doctors, ward doctors and ward nurses, clinicians in all settings appeared to prioritise certain types of tasks over others. Documentation was generally given low priority in all groups, while the arrival of direct care tasks tended to be treated with high priority. These findings suggest that considerations of safety may be implicit in task-switching and multitasking decisions. Although these strategies have been cast in a negative light, future research should consider their role in optimising competing quality and efficiency demands.

Trends in mortality after diagnosis of hepatitis B or C infection: 1992–2006

BACKGROUND & AIMS Chronic hepatitis B (HBV) or C (HCV) virus infection has been associated with increased risk of death, particularly from liver- and drug-related causes. We examined specific causes of death among a population-based cohort of people infected with HBV or HCV to identify areas of excess risk and examine trends in mortality. METHODS HBV and HCV cases notified to the New South Wales (NSW) Health Department between 1992 and 2006 were linked to cause of death data and HIV/AIDS notifications. Mortality rates and standardised mortality ratios (SMRs) were calculated using person time methodology, with NSW population rates used as a comparison. RESULTS The study cohort comprised 42,480 individuals with HBV mono-infection and 82,034 with HCV mono-infection. HIV co-infection increased the overall mortality rate three to 10-fold compared to mono-infected groups. Liver-related deaths were associated with high excess risk of mortality in both HBV and HCV groups (SMR 10.0, 95% CI 9.0-11.1; 15.8, 95% CI 14.8-16.8). Drug-related deaths among the HCV group also represented an elevated excess risk (SMR 15.4, 95% CI 14.5-16.3). Rates of hepatocellular carcinoma (HCC)-related death remained steady in both groups. A decrease in non-HCC liver-related deaths was seen in the HBV group between 1997 and 2006, but not in the HCV group. After a sharp decrease between 1999 and 2002, drug-related mortality rates in the HCV group have been stable. CONCLUSIONS Improvements in HBV treatment and uptake have most likely reduced non-HCC liver-related mortality. Encouragingly, HCV drug-related mortality remained low compared to pre-2002 levels, likely due to changes in opiate supply, and maintenance or improvement in harm reduction strategies.

Risk factors for hepatocellular carcinoma in a cohort infected with hepatitis B or C.

Background and Aim:  The incidence of hepatocellular carcinoma (HCC) has increased in Australia in recent decades, a large and growing proportion of which occurs among a population chronically infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). However, risk factors for HCC among these high‐risk groups require further characterization.

Long term bicycle related head injury trends for New South Wales, Australia following mandatory helmet legislation

Since the 1991 enactment of mandatory helmet legislation (MHL) for cyclists in New South Wales (NSW), Australia, there has been extensive debate as to its effect on head injury rates at a population level. Many previous studies have focused on the impact of MHL around the time of enactment, while little has been done to examine the ongoing effects. We aimed to extend prior work by investigating long-term trends in cyclist head and arm injuries over the period 1991-2010. The counts of cyclists hospitalised with head or arm injuries were jointly modelled with log-linear regression. The simultaneous modelling of related injury mechanisms avoids the need for actual exposure data and accounts for the effects of changes in the cycling environment, cycling behaviour and general safety improvements. Models were run separately with population counts, bicycle imports, the average weekday counts of cyclists in Sydney CBD and cycling estimates from survey data as proxy exposures. Overall, arm injuries were higher than head injuries throughout the study period, consistent with previous post-MHL observations. The trends in the two injury groups also significantly diverged, such that the gap between rates increased with time. The results suggest that the initial observed benefit of MHL has been maintained over the ensuing decades. There is a notable additional safety benefit after 2006 that is associated with an increase in cycling infrastructure spending. This implies that the effect of MHL is ongoing and progress in cycling safety in NSW has and will continue to benefit from focusing on broader issues such as increasing cycling infrastructure.

Trends in incidence of hepatocellular carcinoma after diagnosis of hepatitis B or C infection: a population-based cohort study, 1992-2007.

Summary.  Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the major risk factors for hepatocellular carcinoma (HCC). We examined trends in the incidence of HCC among a population‐based cohort of people infected with HBV or HCV. HBV and HCV cases notified to the New South Wales Health Department between 1992 and 2007 were linked to the Central Cancer Registry, Registry of Births, Deaths and Marriages, and National HIV/AIDS Registries. Crude HCC incidence rates were estimated using person‐time methodology. Age‐standardized incidence rates were calculated using the 2001 Australian population. Trends in incidence were examined using join point regression models. Between 1992 and 2007, 1201 people had a linked HCC record: 556 of those with HBV; 592 with HCV; 45 with HBV/HCV co‐infection; and 8 with HIV co‐infection. The overall age‐standardized HCC incidence rates declined non‐significantly from 148.0 (95% confidence intervals (CI) 63.7, 287.4) per 100 000 population in 1995 to 101.2 (95% CI 67.3, 144.6) in 2007 among the HBV monoinfected group and significantly from 151.8 (95% CI 62.4, 299.8) per 100 000 population to 75.3 (95% CI 50.8, 105.5) among the HCV monoinfected group. However, incidence rates in the HCV monoinfected group progressively increased from the period 1992–1997 to 2004–2007 when adjusted for age, sex, and birth cohort, and the total number of cases per annum continued to increase. Despite declines in the age‐adjusted incidence rates of HCC over time, the absolute number of cases increased likely due to the ageing cohort and an increasing prevalence of both hepatitis B and C in Australia.

Improving our understanding of multi-tasking in healthcare: Drawing together the cognitive psychology and healthcare literature

Multi-tasking is an important skill for clinical work which has received limited research attention. Its impacts on clinical work are poorly understood. In contrast, there is substantial multi-tasking research in cognitive psychology, driver distraction, and human-computer interaction. This review synthesises evidence of the extent and impacts of multi-tasking on efficiency and task performance from health and non-healthcare literature, to compare and contrast approaches, identify implications for clinical work, and to develop an evidence-informed framework for guiding the measurement of multi-tasking in future healthcare studies. The results showed healthcare studies using direct observation have focused on descriptive studies to quantify concurrent multi-tasking and its frequency in different contexts, with limited study of impact. In comparison, non-healthcare studies have applied predominantly experimental and simulation designs, focusing on interleaved and concurrent multi-tasking, and testing theories of the mechanisms by which multi-tasking impacts task efficiency and performance. We propose a framework to guide the measurement of multi-tasking in clinical settings that draws together lessons from these siloed research efforts.

Trends in mortality after diagnosis of hepatitis C virus infection: An international comparison and implications for monitoring the population impact of treatment

BACKGROUND & AIMS People living with hepatitis C virus (HCV) are at increased risk of all-cause and liver-related mortality, although successful treatment has been shown to reduce this risk. The aim of this study was to provide baseline data on trends in cause-specific mortality and to establish an international surveillance system for evaluating the population level impact of HCV treatments. METHODS Population level HCV diagnosis databases from Scotland (1997-2010), Australia (New South Wales [NSW]) (1997-2006), and Canada (British Columbia [BC]) (1997-2003) were linked to corresponding death registries using record linkage. For each region, age-adjusted cause-specific mortality rates were calculated, and trends in annual age-adjusted liver-related mortality were plotted. RESULTS Of 105,138 individuals diagnosed with HCV (21,810 in Scotland, 58,484 in NSW, and 24,844 in BC), there were 7275 deaths (2572 in Scotland, 2655 in NSW, and 2048 in BC). Liver-related deaths accounted for 26% of deaths in Scotland, 21% in NSW, and 22% in BC. Temporal trends in age-adjusted liver related mortality were stable in Scotland (males p=0.4; females p=0.2) and NSW (males p=0.9; females p=0.9), while there was an increase in BC (males p=0.002; females p=0.04). CONCLUSIONS The risk of liver-related mortality after a diagnosis of HCV has remained stable or increased over time across three regions with well-established diagnosis databases, highlighting that HCV treatment programmes to-date have had minimal impact on population level HCV-related liver disease. With more effective therapies on the horizon, and greater uptake of treatment anticipated, the potential of future therapeutic strategies to reduce HCV-related mortality is considerable.

Bringing cohort studies to the bedside: framework for a 'green button' to support clinical decision-making

When providing care, clinicians are expected to take note of clinical practice guidelines, which offer recommendations based on the available evidence. However, guidelines may not apply to individual patients with comorbidities, as they are typically excluded from clinical trials. Guidelines also tend not to provide relevant evidence on risks, secondary effects and long-term outcomes. Querying the electronic health records of similar patients may for many provide an alternate source of evidence to inform decision-making. It is important to develop methods to support these personalized observational studies at the point-of-care, to understand when these methods may provide valid results, and to validate and integrate these findings with those from clinical trials.