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

Carers National Data Repository scoping study: final report

The Department of Health and Ageing (DoHA) commissioned AIHW to undertake this study to investigate and document the scope, feasibility and utility of setting up a Carers National Data Repository (CNDR). The CNDR is conceived as a way of improving the evidence available about carers using existing data which would mitigate issues arising from scattered evidence by bringing data together, standardising metadata and analysing data in more integrated ways (including through the use of data linkage) to inform important policy and research issues

The Hospital Dementia Services Project: Age differences in hospital stays for older people with and without dementia

ABSTRACTBackground:People with dementia may have adverse outcomes following periods of acute hospitalization. This study aimed to explore the effects of age upon hospitalization outcomes for patients with dementia in comparison to patients without dementia.Methods:Data extracted from the New South Wales Admitted Patient Care Database for people aged 50 years and over for the period July 2006 to June 2007 were linked to create person-based records relating to both single and multiple periods of hospitalization. This yielded nearly 409,000 multi-day periods of hospitalization relating to almost 253,000 persons. Using ICD-10-AM codes for dementia and other principal diagnoses, the relationship between age and hospitalization characteristics were examined for people with and without dementia.Results:Dementia was age-related, with 25% of patients aged 85 years and over having dementia compared with 0.9% of patients aged 50–54 years. People with dementia were more likely to be admitted for fractured femurs, lower respiratory tract infections, urinary tract infections and head injuries than people without dementia. Mean length of stay for admissions for people with dementia was 16.4 days and 8.9 days for those without dementia. People with dementia were more likely than those without to be re-admitted within three months for another multi-day stay. Mortality rates and transfers to nursing home care were higher for people with dementia than for people without dementia. These outcomes were more pronounced in younger people with dementia.Conclusion:Outcomes of hospitalization vary substantially for patients with dementia compared with patients without dementia and these differences are frequently most marked among patients aged under 65 years.</jats:p

Alcohol-related cognitive impairment in New South Wales hospital patients aged 50 years and over

Objectives: The aim of this study was to describe the principal reasons for admission, medical comorbidities, interventions and outcomes of patients admitted to New South Wales hospitals with alcohol-related cognitive impairment. Methods: We extracted data from the NSW Admitted Patient Care Database for nearly 410 000 multi-day hospital admissions from 222 public hospitals ending between July 2006 and June 2007 for people aged 50 and over. Data linkage using a unique patient identifier, derived by the Centre for Health Record Linkage identified hospital transfers and readmissions for individual patients. Using ICD10-AM codes, we identified patients with alcohol-related dementia, amnesic syndrome due to alcohol, and Wernicke's encephalopathy, their principal reasons for admission and medical comorbidities, and procedures undertaken. Outcomes were length of stay, mortality, discharge destination, and readmission. Results: A total of 462 patients diagnosed with alcohol-related dementia (n = 300; 82% male, mean age 63.9 years), Wernicke's encephalopathy (n = 77) or amnesic syndrome due to alcohol (n = 126) were identified with overlap between diagnoses. Alcohol-related dementia occurred in 1.4% of dementia patients, and was more likely to occur in younger age groups and men than other types of dementia. Alcohol-related mental disorder was recorded in 70% of alcohol-related dementia multi-day admissions: dependence (52%), ‘harmful use’ (11%) and withdrawal (12%). Principal reasons for admission for multi-day stays included alcohol-related mental disorder (18%), liver disease (11%) and injuries/poisonings (10%). Medical comorbidity was common. Like other dementia patients, alcohol-related dementia patients had longer length of stay (mean of 15 days) than non-dementia patients and more transfers to residential care (7%). However, mortality was similar to non-dementia patients (5%). Discharge at own risk was high (3.7%). Conclusions: Alcohol-related dementia is a preventable and potentially reversible condition. Investigation of intervention strategies initiated during hospitalization are warranted. </jats:p