Linkage of health and aged care service events: comparing linkage and event selection methods

<p>Abstract</p> <p>Background</p> <p>Data linkage is a technique that has long been used to connect information across several disparate data sources – most commonly for medical and population health research. Often the purpose is to connect data for individuals over extended time periods or across different service settings, and so person-based linkage using detailed personal information is preferred. Linkage which aims to link connected events, on the other hand, requires information about the time and place of the event as well as the person or persons involved in that event in order to make high quality linkages.</p> <p>This paper describes the detailed process of event linkage and compares directly an event-based linkage method for identifying transition events between two care sectors in Australia with a well-established high quality longitudinal person-based linkage which facilitates identification of event data for individuals.</p> <p>Methods</p> <p>Direct comparisons are made between transition events identified using an event-based linkage and an existing person-based linkage for people moving from hospital into aged care in Western Australia. Several aspects of event-based linkage are examined: refinement of the strategy to reduce false positives, causes of false positives and false negatives, quality of the linked event dataset, and utility of the linked event dataset for transition analysis.</p> <p>Results</p> <p>Over 97% of the event-based links were among those selected using the person-based linkage and over 90% of the latter were identified by the event-based method, with the remainder missed mostly due to differences in reported event date or residential region. Consequently the two linked datasets were sufficiently similar to give very similar results for analyses, but the actual volume of movement from hospital to RAC was underestimated by about 10% by the event-based method.</p> <p>Conclusion</p> <p>This project has allowed a 'preferred event' event-based linkage strategy to be selected and deployed across Australia to study movements from hospital to residential aged care facilities using databases in which only limited personal information is available, but event dates and details can be readily accessed. The utility of this approach in other transition situations depends on the volume of movement and the accuracy of recording information in each setting.</p

Empirical aspects of record linkage across multiple data sets using statistical linkage keys: the experience of the PIAC cohort study

Background. In Australia, many community service program data collections developed over the last decade, including several for aged care programs, contain a statistical linkage key (SLK) to enable derivation of client-level data. In addition, a common SLK is now used in many collections to facilitate the statistical examination of cross-program use. In 2005, the Pathways in Aged Care (PIAC) cohort study was funded to create a linked aged care database using the common SLK to enable analysis of pathways through aged care services. Linkage using an SLK is commonly deterministic. The purpose of this paper is to describe an extended deterministic record linkage strategy for situations where there is a general person identifier (e.g. an SLK) and several additional variables suitable for data linkage. This approach can allow for variation in client information recorded on different databases. Methods. A stepwise deterministic record linkage algorithm was developed to link datasets using an SLK and several other variables. Three measures of likely match accuracy were used: the discriminating power of match key values, an estimated false match rate, and an estimated step-specific trade-off between true and false matches. The method was validated through examining link properties and clerical review of three samples of links. Results. The deterministic algorithm resulted in up to an 11% increase in links compared with simple deterministic matching using an SLK. The links identified are of high quality: validation samples showed that less than 0.5% of links were false positives, and very few matches were made using non-unique match information (0.01%). There was a high degree of consistency in the characteristics of linked events. Conclusions. The linkage strategy described in this paper has allowed the linking of multiple large aged care service datasets using a statistical linkage key while allowing for variation in its reporting. More widely, our deterministic algorithm, based on statistical properties of match keys, is a useful addition to the linker's toolkit. In particular, it may prove attractive when insufficient data are available for clerical review or follow-up, and the researcher has fewer options in relation to probabilistic linkage

Potentially preventable complications of urinary tract infections, pressure areas, pneumonia, and delirium in hospitalised dementia patients: Retrospective cohort study

OBJECTIVES: To identify rates of potentially preventable complications for dementia patients compared with non-dementia patients. DESIGN: Retrospective cohort design using hospital discharge data for dementia patients, case matched on sex, age, comorbidity and surgical status on a 1 : 4 ratio to non-dementia patients. SETTING: Public hospital discharge data from the state of New South Wales, Australia for 2006/2007. PARTICIPANTS: 426 276 overnight hospital episodes for patients aged 50 and above (census sample). MAIN OUTCOME MEASURES: Rates of preventable complications, with episode-level risk adjustment for 12 complications that are known to be sensitive to nursing care. RESULTS: Controlling for age and comorbidities, surgical dementia patients had higher rates than non-dementia patients in seven of the 12 complications: urinary tract infections, pressure ulcers, delirium, pneumonia, physiological and metabolic derangement (all at p<0.0001), sepsis and failure to rescue (at p<0.05). Medical dementia patients also had higher rates of these complications than did non-dementia patients. The highest rates and highest relative risk for dementia patients compared with non-dementia patients, in both medical and surgical populations, were found in four common complications: urinary tract infections, pressure areas, pneumonia and delirium. CONCLUSIONS: Compared with non-dementia patients, hospitalised dementia patients have higher rates of potentially preventable complications that might be responsive to nursing interventions

Event-based record linkage in health and aged care services data: a methodological innovation

<p>Abstract</p> <p>Background</p> <p>The interface between acute hospital care and residential aged care has long been recognised as an important issue in aged care services research in Australia. However, existing national data provide very poor information on the movements of clients between the two sectors. Nevertheless, there are national data sets which separately contain data on individuals' hospital episodes and stays in residential aged care, so that linking the two data sets–if feasible–would provide a valuable resource for examining relationships between the two sectors. As neither name nor common person identifiers are available on the data sets, other information needs to be used to link events relating to inter-sector movement.</p> <p>Methods</p> <p>Event-based matching using limited demographic data in conjunction with event dates to match events in two data sets provides a possible method for linking related events. The authors develop a statistical model for examining the likely prevalence of false matches, and consequently the number of true matches, among achieved matches when using anonymous event-based record linkage to identify transition events.</p> <p>Results</p> <p>Theoretical analysis shows that for event-based matching the prevalence of false matches among achieved matches (a) declines as the events of interest become rarer, (b) declines as the number of matches increases, and (c) increases with the size of the population within which matching is taking place. The method also facilitates the examination of the trade-off between false matches and missed matches when relaxing or tightening linkage criteria.</p> <p>Conclusion</p> <p>Event-based record linkage is a method for linking related transition events using event dates and basic demographic variables (other than name or person identifier). The likely extent of false links among achieved links depends on the two event rates, the match rate and population size. Knowing these, it is possible to gauge whether, for a particular study, event-based linkage could provide a useful tool for examining movements. Analysis shows that there is a range of circumstances in which event-based record linkage could be applied to two event-level databases to generate a linked database useful for transition analysis.</p

Predicting excess cost for older inpatients with clinical complexity:A retrospective cohort study examining cognition, comorbidities and complications

Hospital-acquired complications increase length of stay and contribute to poorer patient outcomes. Older adults are known to be at risk for four key hospital-acquired complications (pressure injuries, pneumonia, urinary tract infections and delirium). These complications have been identified as sensitive to nursing characteristics such as staffing levels and level of education. The cost of these complications compared to the cost of admission severity, dementia, other comorbidities or age has not been established.To investigate costs associated with nurse-sensitive hospital-acquired complications in an older patient population 157,178 overnight public hospital episodes for all patients over age 50 from one Australian state, 2006/07 were examined. A retrospective cohort study design with linear regression analysis provided modelling of length-of-stay costs. Explanatory variables included patient age, sex, comorbidities, admission severity, dementia status, surgical status and four complications. Extra costs were based on above-average length-of-stay for each patient's Diagnosis Related Group from hospital discharge data.For adults over 50 who have length of stay longer than average for their diagnostic condition, comorbid dementia predicts an extra cost of A$874, (US$1,247); any one of four key complications predicts A$812 (US$1,159); each increase in admission severity score predicts A$295 ($US421); each additional comorbidity predicts A$259 (US$370), and for each year of age above 50 predicts A$20 (US$29) (all estimates significant at p<0.0001).Hospital-acquired complications and dementia cost more than other kinds of inpatient complexity, but admission severity is a better predictor of excess cost. Because complications are potentially preventable and dementia care in hospitals can be improved, risk-reduction strategies for common complications, particularly for patients with dementia could be cost effective.Complications and dementia were found to cost more than other kinds of inpatient complexity

Event-based record linkage in health and aged care services data: a methodological innovation-0

<p><b>Copyright information:</b></p><p>Taken from "Event-based record linkage in health and aged care services data: a methodological innovation"</p><p>http://www.biomedcentral.com/1472-6963/7/154</p><p>BMC Health Services Research 2007;7():154-154.</p><p>Published online 25 Sep 2007</p><p>PMCID:PMC2254617.</p><p></p

Event-based record linkage in health and aged care services data: a methodological innovation-1

<p><b>Copyright information:</b></p><p>Taken from "Event-based record linkage in health and aged care services data: a methodological innovation"</p><p>http://www.biomedcentral.com/1472-6963/7/154</p><p>BMC Health Services Research 2007;7():154-154.</p><p>Published online 25 Sep 2007</p><p>PMCID:PMC2254617.</p><p></p

Linkage of health and aged care service events: comparing linkage and event selection methods-1

<p><b>Copyright information:</b></p><p>Taken from "Linkage of health and aged care service events: comparing linkage and event selection methods"</p><p>http://www.biomedcentral.com/1472-6963/8/149</p><p>BMC Health Services Research 2008;8():149-149.</p><p>Published online 17 Jul 2008</p><p>PMCID:PMC2488340.</p><p></p