Male sexual assault: Physical injury and vulnerability in 103 presentations.

OBJECTIVES: To i) describe the demographic and assault characteristics of males alleging recent sexual assault, ii) determine the severity and frequency of general body injury and the frequency of anal and genital injury, iii) identify vulnerability factors and assault characteristics associated with injury. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 103 post-pubertal males attending SARC from Jan-2009 to Dec-2016. METHODS: Men underwent a standardised medical examination and data collection by forensically trained doctors following consent for general body and/or ano-genital examination. Men were considered vulnerable if at least one of the following factors was present: current mental illness; intellectual or physical disability; alcohol intoxication; previous sexual victimization; living in prison or homeless (no fixed address), aged < 18 years. Statistical analysis was performed by Fisher exact test. An algorithm was used to classify general body injuries as mild, moderate or severe. RESULTS: At least one vulnerability factor was present in 88.3% of the 103 men. More than one factor was present in 54.4%. General body injury was observed in 58.0% (40/69) of men consenting to general body examination; 46.4%, 10.1% and 1.4% were classified as having respectively, mild, moderate and severe injuries. Three assault characteristics were associated with general body injury: the use of blunt force (p = 0.002), multiple assailants (p = 0.049) and deprivation of liberty (p = 0.040). Genital injury and anal injury was observed in, respectively, 6.5% (5/77) and 14.3% (11/77) of men consenting to ano-genital examination. Of the 49 men examined following completed penetrative anal assault, 18.4% (9/49) had anal injuries. In these 49 men, those assaulted by strangers were more likely to have an anal injury compared to non-stranger assaults (p = 0.019). No demographic, clinical or vulnerability characteristics of the sexually assaulted men were associated with general body, genital and/or anal injury. CONCLUSION: Although general body injuries were more frequent than genital and anal injuries, most of the body injuries were mild in severity. While the majority of men in our study presented with one or more vulnerabilities only assault characteristics (not vulnerabilities) were associated with injury.

Capturing sexual assault data: An information system designed by forensic clinicians and healthcare researchers.

BACKGROUND: The Sexual Assault Resource Center (SARC) in Perth, Western Australia provides free 24-hour medical, forensic, and counseling services to persons aged over 13 years following sexual assault. OBJECTIVE: The aim of this research was to design a data management system that maintains accurate quality information on all sexual assault cases referred to SARC, facilitating audit and peer-reviewed research. METHODS: The work to develop SARC Medical Services Clinical Information System (SARC-MSCIS) took place during 2007-2009 as a collaboration between SARC and Curtin University, Perth, Western Australia. Patient demographics, assault details, including injury documentation, and counseling sessions were identified as core data sections. A user authentication system was set up for data security. Data quality checks were incorporated to ensure high-quality data. RESULTS: An SARC-MSCIS was developed containing three core data sections having 427 data elements to capture patient's data. Development of the SARC-MSCIS has resulted in comprehensive capacity to support sexual assault research. Four additional projects are underway to explore both the public health and criminal justice considerations in responding to sexual violence. The data showed that 1,933 sexual assault episodes had occurred among 1881 patients between January 1, 2009 and December 31, 2015. Sexual assault patients knew the assailant as a friend, carer, acquaintance, relative, partner, or ex-partner in 70% of cases, with 16% assailants being a stranger to the patient. CONCLUSION: This project has resulted in the development of a high-quality data management system to maintain information for medical and forensic services offered by SARC. This system has also proven to be a reliable resource enabling research in the area of sexual violence.

Sexual assault and general body injuries: A detailed cross-sectional Australian study of 1163 women.

OBJECTIVES: To describe the frequency and severity of general body injury in women alleging recent sexual assault and then identify demographic and assault characteristics associated with injury severity. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 1163 women attending SARC from Jan-2009 to Mar-2015. METHODS: Women underwent a standardised medical examination and data collection by forensically trained doctors. Multivariate ordinal logistic regression analyses were performed. An algorithm was used to classify general body injuries as mild, moderate or severe. RESULTS: General body injury was observed in 71% of women; 52%, 17% and 2% were classified as having respectively, mild, moderate and severe injuries. Moderate or severe injury was observed in 30.4% of women assaulted by intimate partners, 16.4% of women assaulted by strangers and 14.9% of women assaulted by friends/acquaintances. In regression analysis, an interaction between mental illness and assailant type existed after adjusting for age, intellectual disability, time-to-examination, number of assailants and location. Mental illness was an independent predictor for lower injury severity (adjusted odds ratio=0.5, 95% CI 0.3, 0.9) in women assaulted by strangers and higher injury severity in women assaulted by a friend/acquaintance (adjusted odds ratio=2.4, 95% CI 1.6, 3.6). While women assaulted by intimate partners had more frequent moderate-to-severe injuries than other women their current mental illness status was not associated with risk of injury severity. CONCLUSION: This study highlights the increased injury severity in women assaulted by intimate partners. The risk of moderate/severe injury for women with mental illness assaulted by their acquaintances was unexpected and requires further investigation.

The impact of community-based palliative care on acute hospital use in the last year of life is modified by time to death, age and underlying cause of death. A population-based retrospective cohort study.

OBJECTIVE: Community-based palliative care is known to be associated with reduced acute care health service use. Our objective was to investigate how reduced acute care hospital use in the last year of life varied temporally and by patient factors. METHODS: A retrospective cohort study of the last year of life of 12,763 Western Australians who died from cancer or one of seven non-cancer conditions. Outcome measures were rates of hospital admissions and mean length of hospital stays. Multivariate analyses involved time-to-event and population averaged log-link gamma models. RESULTS: There were 28,939 acute care overnight hospital admissions recorded in the last year of life, an average of 2.3 (SD 2.2) per decedent and a mean length of stay of 9.2 (SD 10.3) days. Overall, the rate of hospital admissions was reduced 34% (95%CI 1-66) and the mean length of stay reduced 6% (95%CI 2-10) during periods of time decedents received community-based palliative care compared to periods of time not receiving this care. Decedents aged <70 years receiving community-based palliative care showed a reduced rate of hospital admission around five months before death, whereas for older decedents the reduction in hospital admissions was apparent a year before death. All decedents who were receiving community-based palliative care tended towards shorter hospital stays in the last month of life. Decedents with neoplasms had a mean length of stay three weeks prior to death while not receiving community-based palliative care of 9.6 (95%CI 9.3-9.9) days compared to 8.2 (95% CI 7.9-8.7) days when receiving community-based palliative care. CONCLUSION: Rates of hospital admission during periods of receiving community-based palliative care were reduced with benefits evident five months before death and even earlier for older decedents. The mean length of hospital stay was also reduced while receiving community-based palliative care, mostly in the last month of life.

Estimating parameters for probabilistic linkage of privacy-preserved datasets.

BACKGROUND: Probabilistic record linkage is a process used to bring together person-based records from within the same dataset (de-duplication) or from disparate datasets using pairwise comparisons and matching probabilities. The linkage strategy and associated match probabilities are often estimated through investigations into data quality and manual inspection. However, as privacy-preserved datasets comprise encrypted data, such methods are not possible. In this paper, we present a method for estimating the probabilities and threshold values for probabilistic privacy-preserved record linkage using Bloom filters. METHODS: Our method was tested through a simulation study using synthetic data, followed by an application using real-world administrative data. Synthetic datasets were generated with error rates from zero to 20% error. Our method was used to estimate parameters (probabilities and thresholds) for de-duplication linkages. Linkage quality was determined by F-measure. Each dataset was privacy-preserved using separate Bloom filters for each field. Match probabilities were estimated using the expectation-maximisation (EM) algorithm on the privacy-preserved data. Threshold cut-off values were determined by an extension to the EM algorithm allowing linkage quality to be estimated for each possible threshold. De-duplication linkages of each privacy-preserved dataset were performed using both estimated and calculated probabilities. Linkage quality using the F-measure at the estimated threshold values was also compared to the highest F-measure. Three large administrative datasets were used to demonstrate the applicability of the probability and threshold estimation technique on real-world data. RESULTS: Linkage of the synthetic datasets using the estimated probabilities produced an F-measure that was comparable to the F-measure using calculated probabilities, even with up to 20% error. Linkage of the administrative datasets using estimated probabilities produced an F-measure that was higher than the F-measure using calculated probabilities. Further, the threshold estimation yielded results for F-measure that were only slightly below the highest possible for those probabilities. CONCLUSIONS: The method appears highly accurate across a spectrum of datasets with varying degrees of error. As there are few alternatives for parameter estimation, the approach is a major step towards providing a complete operational approach for probabilistic linkage of privacy-preserved datasets.

Genital and anal injuries: A cross-sectional Australian study of 1266 women alleging recent sexual assault.

OBJECTIVES: To describe the frequency of genital and anal injury and associated demographic and assault characteristics in women alleging sexual assault. DESIGN: Cross-sectional study. SETTING: Sexual Assault Resource Centre (SARC), Western Australia. PARTICIPANTS: Total of 1266 women attending SARC from Jan-2009 to Mar-2015. METHODS: Women underwent a standardised data collection procedure by forensically trained doctors. Multivariate logistic regression analyses were performed. MAIN OUTCOME MEASURES: (1) Frequency of genital and anal injuries by type of sexual assault. (2) Identification of independent factors associated with genital and anal injuries following, respectively, completed vaginal and anal penetration. RESULTS: Genital injury was observed in 24.5% of all women with reported completed vaginal penetration; in a subset with no prior sexual intercourse 52.1% had genital injury. Genital injury was more likely with no prior sexual intercourse (adjusted odds ratio [adj. OR] 4.4, 95% confidence interval [95%CI] 2.4-8.0), multiple types of penetrants (adj. OR 1.5, 95%CI 1.0-2.1), if general body injury present and less likely with sedative use and delayed examination. Anal injury, observed in 27.0% of reported completed anal penetrations, was more likely with multiple types of penetrants (adjusted OR 5.0, 95%CI 1.2-21.0), if general body injury present and less likely with delayed examination. CONCLUSION: This study separately quantifies the frequency of both genital and anal injuries in sexually assaulted women. Genital injuries were absent in a large proportion of women regardless of prior vaginal intercourse status. It is anticipated that findings will better inform the community, police and medico-legal evidence to the criminal justice system.

Ensuring Privacy When Integrating Patient-Based Datasets: New Methods and Developments in Record Linkage.

In an era where the volume of structured and unstructured digital data has exploded, there has been an enormous growth in the creation of data about individuals that can be used for understanding and treating disease. Joining these records together at an individual level provides a complete picture of a patient's interaction with health services and allows better assessment of patient outcomes and effectiveness of treatment and services. Record linkage techniques provide an efficient and cost-effective method to bring individual records together as patient profiles. These linkage procedures bring their own challenges, especially relating to the protection of privacy. The development and implementation of record linkage systems that do not require the release of personal information can reduce the risks associated with record linkage and overcome legal barriers to data sharing. Current conceptual and experimental privacy-preserving record linkage (PPRL) models show promise in addressing data integration challenges. Enhancing and operationalizing PPRL protocols can help address the dilemma faced by some custodians between using data to improve quality of life and dealing with the ethical, legal, and administrative issues associated with protecting an individual's privacy. These methods can reduce the risk to privacy, as they do not require personally identifying information to be shared. PPRL methods can improve the delivery of record linkage services to the health and broader research community.

Improving the Estimation of Risk-Adjusted Grouped Hospital Standardized Mortality Ratios Using Cross-Jurisdictional Linked Administrative Data: A Retrospective Cohort Study.

BACKGROUND: Hospitals and death registries in Australia are operated under individual state government jurisdictions. Some state borders are located in heavily populated areas or are located near to major capital cities. Mortality indicators for hospital located near state borders may not be estimated accurately if patients are lost as they cross state borders. The aim of this study was to evaluate how cross-jurisdictional linkage of state hospital and death records across state borders may improve estimation of the hospital standardized mortality ratio (HSMR), a tool used in Australia as a hospital performance indicator. METHOD: Retrospective cohort study of 7.7 million hospital patients from July 2004 to June 2009. Inhospital deaths and deaths within 30 days of hospital discharge from four state jurisdictions were used to estimate the standardized mortality ratio of hospital groups defined by geography and type of hospital (grouped HSMR) under three record linkage scenarios, as follows: (1) cross-jurisdictional person-level linkage, (2) within-jurisdictional (state-based) person-level linkage, and (3) unlinked records. All public and private hospitals in New South Wales, Queensland, Western Australia, and public hospitals in South Australia were included in this study. Death registrations from all four states were obtained from state-based registries of births, deaths, and marriages. RESULTS: Cross-jurisdictional linkage identified 11,116 cross-border hospital transfers of which 170 resulted in a cross-border inhospital death. An additional 496 cross-border deaths occurred within 30 days of hospital discharge. The inclusion of cross-jurisdictional person-level links to unlinked hospital records reduced the coefficient of variation among the grouped HSMRs from 0.19 to 0.15; the inclusion of 30-day deaths reduced the coefficient of variation further to 0.11. There were minor changes in grouped HSMRs between cross-jurisdictional and within-jurisdictional linkages, although the impact of cross-jurisdictional linkage increased when restricted to regions with high cross-border hospital use. CONCLUSION: Cross-jurisdictional linkage modified estimates of grouped HSMRs in hospital groups likely to receive a high proportion of cross-border users. Hospital identifiers will be required to confirm whether individual hospital performance indicators change.

The Association of Community-Based Palliative Care With Reduced Emergency Department Visits in the Last Year of Life Varies by Patient Factors.

STUDY OBJECTIVE: Palliative care has been shown to reduce end-of-life emergency department (ED) use. Our objective was to determine how the association of community-based palliative care with reduced ED visits in the last year of life varied by patient factors. METHODS: This was a retrospective cohort study of 11,875 decedents who died with neoplasms, heart failure, renal failure, chronic obstructive pulmonary disease, or liver failure in Western Australia in 2009 to 2010. Outcome measures were adjusted hazard ratios (HRs) and daily (hazard) rates of ED visits. RESULTS: The adjusted average rate of ED visits for the cohort was reduced 50% (HR 0.50; 95% confidence interval [CI] 0.47 to 0.53) during periods of receipt of community-based palliative care. This relative reduction in ED visits varied by patient factors, ranging from 43% (HR 0.57; 95% CI 0.45 to 0.74) for decedents aged 60 years and younger up to 71% (HR 0.29; 95% CI 0.18 to 0.46) for people aged 90 years and older. Decedents living in the most disadvantaged areas had a 44% (HR 0.56; 95% CI 0.44 to 0.72) reduction in ED visits when receiving community-based palliative care compared with a 60% (HR 0.40; 95% CI 0.31 to 0.53) reduction for decedents who lived in the least disadvantaged areas and received this care. The ED visit rates while patients were receiving palliative care also varied by ED visit history, partner status, and region of residence. CONCLUSION: Receipt of community-based palliative care in the last year of life was associated with a reduced rate of ED visits. The magnitude of this association was modified by patient health, as well as social and demographic factors.

Risk of persistent or recurrent neoplasia in conservatively treated women with cervical adenocarcinoma in situ with negative histological margins.

INTRODUCTION: Conservative treatments including cold knife cone biopsy (CKC) or loop electrosurgical excision procedure (LEEP) are fertility-preserving alternatives to hysterectomy. The risks of persistent cervical neoplasia in women with negative surgical margins following conservative treatment of adenocarcinoma-in-situ (AIS) are uncertain. This study aims to investigate the risk of persistent or recurrent cervical neoplasia [AIS, adenocarcinoma and/or high-grade cervical squamous intraepithelial neoplasia (CIN)] and compliance with follow-up recommendations in conservatively treated women with AIS and negative histopathological margins. MATERIAL AND METHODS: A retrospective, population-based study of Western Australian women treated by CKC or LEEP for AIS between 2001 and 2012. Histopathology reports were reviewed for demographic information, treatment procedures and clinicopathological factors. Primary outcomes were the diagnosis of cervical neoplasia during follow-up (defined as <12 months) and surveillance (≥12 months) periods. RESULTS: The cohort comprised 360 women, with 175 (48.6%) initially treated by CKC and 185 (51.4%) treated by LEEP. The median patient age at time of excisional treatment was 30.0 years (range 18-64 years) and the median follow-up time was 3.9 years (range six months to 12.2 years). During the follow-up and surveillance periods, seven (1.9%) women were diagnosed with CIN 2/3, 10 (2.8%) with AIS, and one (0.3%) with cervical adenocarcinoma, despite their initial excision specimens having negative histological margins. CONCLUSION: In this study, there was a low but significant risk of persistent or recurrent cervical neoplasia in women who had initial conservative management of AIS with negative histopathological margins.

Risk of persistent and recurrent cervical neoplasia following incidentally detected adenocarcinoma in situ.

BACKGROUND: Adenocarcinoma in situ of the uterine cervix is a precursor to cervical adenocarcinoma and may coexist with both adenocarcinoma and high-grade squamous dysplasia (cervical intraepithelial neoplasia 2 and 3). Up to 60% of adenocarcinoma in situ lesions are detected incidentally following excisional biopsies performed for the treatment of cervical intraepithelial neoplasia 2/3. To date there are no data regarding risk factors for persisting or progressive cervical neoplasia in these patients. OBJECTIVE: We sought to investigate patient outcomes following incidentally detected cervical adenocarcinoma in situ after loop electrosurgical excision procedure or cold knife cone biopsy performed for the treatment of high-grade cervical intraepithelial neoplasia. STUDY DESIGN: We conducted a retrospective, population-based cohort study of Western Australian patients with an incidental diagnosis of adenocarcinoma in situ from 2001 through 2012. Primary outcomes were persistent or recurrent cervical intraepithelial neoplasia 2/3 and or adenocarcinoma in situ, and invasive adenocarcinoma during follow-up (<12 months) and surveillance (≥12 months) periods. RESULTS: The cohort comprised 298 patients, with 228 (76.5%) treated initially by loop electrosurgical excision procedure and 70 (23.5%) treated by cold knife cone biopsy. The mean age was 31.2 (range 18-68) years and the median length of follow-up was 2.4 (range 0.3-12.2) years. Overall, 11 (3.7%) patients had cervical intraepithelial neoplasia 2/3, 23 (7.7%) had adenocarcinoma in situ, and 3 (1.0%) had adenocarcinoma diagnosed during the follow-up and surveillance periods. Age >30 years, pure adenocarcinoma in situ lesions, and larger lesions (>8 mm) were associated with a greater risk of disease persistence or recurrence. CONCLUSION: Following the incidental detection of adenocarcinoma in situ, age >30 years, pure adenocarcinoma in situ lesions, and lesions >8 mm were significantly associated with disease persistence/recurrence. In younger women, incidentally detected adenocarcinoma in situ that coexists with cervical intraepithelial neoplasia 2/3 and is <8 mm extent with clear margins may not require reexcision.

Non-fatal strangulation in sexual assault: A study of clinical and assault characteristics highlighting the role of intimate partner violence.

OBJECTIVE: To describe the prevalence, risk factors, signs and symptoms of non-fatal strangulation (NFS) in women referred to a Sexual Assault Resource Centre (SARC) following recent sexual assault. METHODS: A cross-sectional study using data routinely collected at time of forensic examination of women (age ≥ 13 years) referred to the Western Australian SARC between Jan-2009 and Mar-2015 alleging a recent sexual assault. Data on demographics, assault characteristics and forensic findings were available. RESULTS: A total of 1064 women were included in the study; 79 (7.4%) alleged NFS during the sexual assault. The prevalence of NFS varied significantly by age-group and assailant type. Of women aged 30-39 years 15.1% gave a history of NFS compared to less than 8.2% in all other age groups. Of women assaulted by an intimate partner, 22.5% gave a history of NFS compared to less than 6% of women assaulted by other assailant types. Of all sexual assaults with NFS, intimate partners were the assailant in 58.2% of cases, whereas in sexual assault cases without NFS, intimate partners were the assailant in 15.9% of cases. Odds of NFS were 8.4 times higher in women sexually assaulted by an intimate partner compared to women assaulted by an acquaintance/friend and 4.9 times higher compared to women assaulted by a stranger. When considering both age and assailant type the highest proportion of NFS (33.9%) was in women aged 30-39 years sexually assaulted by an intimate partner. Other factors associated with NFS during sexual assault included deprivation of liberty, verbal threats, being assaulted in the woman's home and use of additional blunt force. External physical signs of NFS were absent in 49.4% of all NFS sexual assault cases. CONCLUSIONS: This study identifies and quantifies NFS risk factors in female sexual assault and highlights the strong association with intimate partner sexual assault. Greater awareness of NFS in sexual assault should lead to improvement in medical screening, forensic management and safety risk assessment by sexual assault and domestic violence services, emergency departments and police.

Limited privacy protection and poor sensitivity: Is it time to move on from the statistical linkage key-581?

BACKGROUND: The statistical linkage key (SLK-581) is a common tool for record linkage in Australia, due to its ability to provide some privacy protection. However, newer privacy-preserving approaches may provide greater privacy protection, while allowing high-quality linkage. OBJECTIVE: To evaluate the standard SLK-581, encrypted SLK-581 and a newer privacy-preserving approach using Bloom filters, in terms of both privacy and linkage quality. METHOD: Linkage quality was compared by conducting linkages on Australian health datasets using these three techniques and examining results. Privacy was compared qualitatively in relation to a series of scenarios where privacy breaches may occur. RESULTS: The Bloom filter technique offered greater privacy protection and linkage quality compared to the SLK-based method commonly used in Australia. CONCLUSION: The adoption of new privacy-preserving methods would allow both greater confidence in research results, while significantly improving privacy protection.

A retrospective population based cohort study of access to specialist palliative care in the last year of life: who is still missing out a decade on?

BACKGROUND: Historically, specialist palliative care has been accessed by a greater proportion of people dying with cancer compared to people with other life-limiting conditions. More recently, a variety of measures to improve access to palliative care for people dying from non-cancer conditions have been implemented. There are few rigorous population-based studies that document changes in palliative care service delivery relative to the number of patients who could benefit from such services. METHOD: A retrospective cohort study of the last year of life of persons with an underlying cause of death in 2009-10 from cancer, heart failure, renal failure, liver failure, chronic obstructive pulmonary disease, Alzheimer's disease, motor neurone disease, Parkinson's disease, Huntington's disease and/or HIV/AIDS. The proportion of decedents receiving specialist palliative care was compared to a 2000-02 cohort. Logistic regression models were used identify social and demographic factors associated with accessing specialist palliative care. RESULTS: There were 12,817 deaths included into the cohort; 7166 (56 %) from cancer, 527 (4 %) from both cancer and non-cancer conditions and 5124 (40 %) from non-cancer conditions. Overall, 46.3 % of decedents received community and/or hospital based specialist palliative care; a 3.5 % (95 % CI 2.3-4.7) increase on specialist palliative care access reported ten years earlier. The majority (69 %; n = 4928) of decedents with cancer accessed palliative care during the last year of life. Only 14 % (n = 729) of decedents with non-cancer conditions accessed specialist palliative care, however, this represented a 6.1 % (95 % CI 4.9-7.3) increase on the specialist palliative care access reported for the same decedent group ten years earlier. Compared to decedents with heart failure, increased odds of palliative care access was observed for decedents with cancer (OR 10.5; 95 % CI 9.1-12.2), renal failure (OR 1.5; 95 % CI 1.3-1.9), liver failure (OR 2.3; 95 % CI 1.7-3.3) or motor neurone disease (OR 4.5; 95 % CI 3.1-6.6). Living in major cities, being female, having a partner and living in a private residence was associated with increased odds of access to specialist palliative care. CONCLUSION: There is small but significant increase in access to specialist palliative care services in Western Australia, specifically in patients dying with non-cancer conditions.

A Simple Sampling Method for Estimating the Accuracy of Large Scale Record Linkage Projects.

BACKGROUND: Record linkage techniques allow different data collections to be brought together to provide a wider picture of the health status of individuals. Ensuring high linkage quality is important to guarantee the quality and integrity of research. Current methods for measuring linkage quality typically focus on precision (the proportion of incorrect links), given the difficulty of measuring the proportion of false negatives. OBJECTIVES: The aim of this work is to introduce and evaluate a sampling based method to estimate both precision and recall following record linkage. METHODS: In the sampling based method, record-pairs from each threshold (including those below the identified cut-off for acceptance) are sampled and clerically reviewed. These results are then applied to the entire set of record-pairs, providing estimates of false positives and false negatives. This method was evaluated on a synthetically generated dataset, where the true match status (which records belonged to the same person) was known. RESULTS: The sampled estimates of linkage quality were relatively close to actual linkage quality metrics calculated for the whole synthetic dataset. The precision and recall measures for seven reviewers were very consistent with little variation in the clerical assessment results (overall agreement using the Fleiss Kappa statistics was 0.601). CONCLUSIONS: This method presents as a possible means of accurately estimating matching quality and refining linkages in population level linkage studies. The sampling approach is especially important for large project linkages where the number of record pairs produced may be very large often running into millions.

Big data and ophthalmic research.

Large population-based health administrative databases, clinical registries, and data linkage systems are a rapidly expanding resource for health research. Ophthalmic research has benefited from the use of these databases in expanding the breadth of knowledge in areas such as disease surveillance, disease etiology, health services utilization, and health outcomes. Furthermore, the quantity of data available for research has increased exponentially in recent times, particularly as e-health initiatives come online in health systems across the globe. We review some big data concepts, the databases and data linkage systems used in eye research-including their advantages and limitations, the types of studies previously undertaken, and the future direction for big data in eye research.

Red blood cell transfusion is associated with further bleeding and fresh-frozen plasma with mortality in nonvariceal upper gastrointestinal bleeding.

BACKGROUND: Blood products are commonly transfused for patients with nonvariceal upper gastrointestinal bleeding (NVUGIB). While concerns exist about further bleeding and mortality in subsets of patients receiving red blood cell (RBC) transfusion, the impact of non-RBC blood products has not previously been systematically investigated. The aim of the study was to investigate the associations between blood products transfusion, further bleeding, and mortality after acute NVUGIB. STUDY DESIGN AND METHODS: A retrospective cohort study examined further bleeding and 30-day and 1-year mortality in adult patients who underwent gastroscopy for suspected acute NVUGIB between 2008 and 2010 in three tertiary hospitals in Western Australia. Survival analysis was performed. RESULTS: A total of 2228 adults (63% male) with 2360 hospital admissions for NVUGIB met the inclusion criteria. Median age at presentation was 70 years (range, 19-99 years). Thirty-day mortality was 4.9% and 1-year mortality was 13.9%. Transfusion of 4 or more units of RBCs was associated with greater than 10 times the odds of further bleeding in patients with a hemoglobin level of more than 90 g/L (odds ratio, 11.9; 95% confidence interval [CI], 3.1-45.7; p ≤ 0.001), but was not associated with mortality. Administration of 5 or more units of fresh-frozen plasma (FFP) was associated with increased 30-day (hazard ratio, 2.8; 95% CI, 1.3-5.9; p = 0.008) and 1-year (hazard ratio, 2.6; 95% CI, 1.3-5.0; p = 0.005) mortality after adjusting for coagulopathy, comorbidity, Rockall score, and other covariates. CONCLUSION: In this large, multicenter study of NVUGIB, RBC transfusion was associated with further bleeding but not mortality, while FFP transfusion was associated with increased mortality in a subset of patients.

Spontaneous regression of CIN2 in women aged 18-24 years: a retrospective study of a state-wide population in Western Australia.

INTRODUCTION: CIN2 has a high rate of spontaneous regression in young women and may be managed conservatively in appropriately selected patients. This study aimed to investigate health outcomes in women aged 18-24 years with biopsy-confirmed CIN2. MATERIAL AND METHODS: A retrospective cohort study of Western Australian women aged 18-24 years diagnosed with CIN2 on cervical biopsy from 1 January 2001 to 31 December 2010. Women who had not received treatment at ≥4 months following CIN2 diagnosis were classified as managed 'conservatively'. Subsequent cervical cytology and/or biopsy test results were used to report lesion regression (absence of dysplasia or an epithelial lesion of lower grade than CIN2) and disease persistence (CIN2, CIN3 or ACIS). RESULTS: Follow-up data were available for 2417 women of whom 924 (38.2%) were 'conservatively' managed. In all, 152 (16.4%) conservatively managed women had a lesion more severe than CIN2 detected within 24 months of initial diagnosis, of which 144 were CIN3 and eight were ACIS. There was no statistically significant association between rates of regression and patient age, Socio-economic Indexes for Areas or Accessibility/Remoteness Index of Australia indices. The 2-year regression rate for CIN2 was estimated to be 59.5% (95%CI 0.5-0.6) in this cohort of women. CONCLUSION: In conservatively managed young women with CIN2 there was a high rate of spontaneous disease regression. Thus, excisional or ablative treatments may be avoided in selected patients who receive appropriate counseling and who are able to comply with more intensive and prolonged follow-up requirements.

Health Service Use and Mortality of the Elderly Blind.

PURPOSE: To determine whether blindness in older people is associated with increased health service use and mortality. DESIGN: Retrospective matched cohort study from July 1, 1999, through June 30, 2010. PARTICIPANTS: A blind cohort 65 years of age and older from a volunteer blind register and a cohort of age- and gender-matched controls selected randomly from the Western Australian electoral roll. METHODS: Person-level linked hospital, emergency department (ED), mental health, and death records for the blind and control cohorts were used. Generalized estimating equations assuming a negative binomial distribution were used to estimate relative rates of hospital admissions, lengths of stay, and mortality after adjusting for sociodemographic variables and comorbidity. Emergency department and mental health service visits also were quantified. MAIN OUTCOME MEASURES: Relative rates of hospital admissions, lengths of stay, and mortality, as well as crude proportions of ED and mental health service visits. RESULTS: The blind cohort comprised 1726 individuals alongside 1726 matched controls; 39% were men, and the mean age was 83 years. Combined, the cohorts accumulated a total of 34 130 hospital admissions amounting to 201 867 bed-days. After adjusting for the principal reason for hospital admission and comorbidity, the blind cohort was admitted to the hospital 11% (95% confidence interval [CI], 6%-17%) more often than the control cohort. The blind cohort also stayed in the hospital longer than the controls, but this effect varied by age. Blind participants 65 to 69 years of age spent 88% more days (95% CI, 27%-178%) in the hospital compared with age-matched controls, whereas there was no difference in length of stay between the cohorts by 80 years of age (rate ratio, 1.10; 95% CI, 0.97-1.25). A larger proportion of the blind cohort visited a hospital ED and accessed mental health services compared with the control cohort. CONCLUSIONS: Health service use is increased for the elderly blind compared with age-matched controls after accounting for comorbidity. The elderly blind have more hospital admissions, ED visits, and mental health-related visits. The younger elderly blind stay longer in hospital. However, there was no evidence of worse mortality outcomes after adjusting for comorbidity.

Accuracy and completeness of patient pathways--the benefits of national data linkage in Australia.

BACKGROUND: The technical challenges associated with national data linkage, and the extent of cross-border population movements, are explored as part of a pioneering research project. The project involved linking state-based hospital admission records and death registrations across Australia for a national study of hospital related deaths. METHODS: The project linked over 44 million morbidity and mortality records from four Australian states between 1st July 1999 and 31st December 2009 using probabilistic methods. The accuracy of the linkage was measured through a comparison with jurisdictional keys sourced from individual states. The extent of cross-border population movement between these states was also assessed. RESULTS: Data matching identified almost twelve million individuals across the four Australian states. The percentage of individuals from one state with records found in another ranged from 3-5%. Using jurisdictional keys to measure linkage quality, results indicate a high matching efficiency (F measure 97 to 99%), with linkage processing taking only a matter of days. CONCLUSIONS: The results demonstrate the feasibility and accuracy of undertaking cross jurisdictional linkage for national research. The benefits are substantial, particularly in relation to capturing the full complement of records in patient pathways as a result of cross-border population movements. The project identified a sizeable 'mobile' population with hospital records in more than one state. Research studies that focus on a single jurisdiction will under-enumerate the extent of hospital usage by individuals in the population. It is important that researchers understand and are aware of the impact of this missing hospital activity on their studies. The project highlights the need for an efficient and accurate data linkage system to support national research across Australia.