Abstract
Background: Area-based indicators are commonly used to measure and track health outcomes by socio- economic group. This is largely because of the absence of socio-economic information about individuals in health administrative databases. The literature shows that the magnitude of differences in health outcomes varies depending on whether the socio-economic indicators are at the individual level or are area-based. This study compares the two types of indicators.
Data and methods: The data are from a file linking the results of the 1991 Census with deaths that occurred from
1991 to 2000―a 15% sample of the Canadian population aged 25 or older. The socio-economic indicator used for comparison is a material and social deprivation index, in individual and area- based versions. The health indicators are life expectancy and disability-free life expectancy, and risks of mortality and disability.
Results: The individual version of the deprivation index yields wider gaps in life expectancy and disability- free life expectancy than does the area-based version. These gaps vary by sex and geographic setting. However, both versions are associated with inequalities in mortality and disability, independent of each other.
Interpretation: Despite some limitations, area-based socio- economic indicators are useful in assessing inequalities in health. The inequalities that they identify are significant, consistent and reliable and can be tracked through time and for different geographic settings.
Keywords
area-based measure, deprivation, disability-free life expectancy, geography, life expectancy, social inequalities
The quality of reporting of studies of diagnostic accuracy is less than optimal. Complete and accurate reporting is necessary to enable readers to assess the potential for bias in the study and to evaluate the generalizability of the results.
A group of scientists and editors has developed the STARD (Standards for Reporting of Diagnostic Accuracy) statement to improve the reporting the quality of reporting of studies of diagnostic accuracy. The statement consists of a checklist of 25 items and flow diagram that authors can use to ensure that all relevant information is present.
This explanatory document aims to facilitate the use, under- standing, and dissemination of the checklist. The document contains a clarification of the meaning, rationale, and optimal use of each item on the checklist, as well as a short summary of the available evidence on bias and applicability.
The STARD statement, checklist, flowchart, and this explanation and elaboration document should be useful resources to improve reporting of diagnostic accuracy studies. Complete and informative reporting can only lead to better decisions in health care.
Abstract
Background: Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a) compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b) test for differences in incidence estimates from multiple administrative data case definitions.
Methods: Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos). Generalized linear models were used to test for differences in incidence estimates.
Results: For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions.
Conclusions: The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.
The Manitoba Centre for Health Policy (MCHP) is located within the Department of Community Health Sciences, Faculty of Medicine, University of Manitoba. The mission of MCHP is to provide accurate and timely information to health care decision-makers, analysts and providers, so they can offer services which are effective and efficient in maintaining and improving the health of Manitobans. Our researchers rely upon the unique Population Health Research Data Repository to describe and explain pat- terns of care and profiles of illness, and to explore other factors that influence health, including income, education, employment and social status. This Repository is unique in terms of its comprehensiveness, degree of integration, and orientation around an anonymized population registry.
Members of MCHP consult extensively with government officials, health care administrators, and clinicians to develop a research agenda that is topi- cal and relevant. This strength along with its rigorous academic standards enable MCHP to contribute to the health policy process. MCHP under- takes several major research projects, such as this one, every year under con- tract to Manitoba Health. In addition, our researchers secure external fund- ing by competing for other research grants. We are widely published and internationally recognized. Further, our researchers collaborate with a number of highly respected scientists from Canada, the U.S. and Europe.
We thank the University of Manitoba, Faculty of Medicine, Health Research Ethics Board for their review of this project. The Manitoba Centre for Health Policy complies with all legislative acts and regulations governing the protection and use of sensitive information. We implement strict policies and procedures to protect the privacy and security of anonymized data used to produce this report and we keep the provincial Health Information Privacy Committee informed of all work undertaken for Manitoba Health.
Abstract
Objectives: We sought to test the ability of large health care utilization databases to accurately identify serious bacterial infections and opportunistic infections leading to hospital admission.
Study Design and Setting: We conducted a cross-sectional validation study using patients admitted to hospitals in the administrative database of the Department of Veterans Affairs, VISN 1, between 2001 and 2004. Detailed hospital chart abstraction protocols were developed to define a gold-standard diagnosis of serious bacterial infections and opportunistic infections. Hospital acquired infections were not considered.
Results: A total of 158 patients who were hospitalized for selected bacterial infections and 69 patients for opportunistic infections were identified using ICD-9 discharge diagnoses. The positive predictive values (PPV) of identifying specific bacterial infections that lead to hospital admissions varied between 100% and 66%. All conditions combined yielded a PPV of 80%. Once the gold-standard definition of bacterial conditions was broadened to hospital admissions due to any acute infectious condition, the PPV increased to 90%. Excluding systemic candidiasis, the average PPV for the selected opportunistic infections was 76%.
Conclusion: Our findings suggest that ICD-9 codes of selected serious infections from hospital discharge files can be used as substitutes for chart-based diagnoses.
Abstract
Objective: Population-based identification of patients with a myocardial infarction is limited to patients presenting to hospital with an acute event. We set out to determine if adding physician billing data to hospital discharge data would result in an accurate capture of patients who have had a myocardial infarction.
Methods: We performed a retrospective chart abstraction of 969 randomly selected adult patients using data abstracted from primary care physicians on an electronic medical record in Ontario, Canada, as the reference standard.
Results: An algorithm of 3 physician billings in a one-year period with at least one being by a specialist or within a hospital or emergency room plus one hospital discharge abstract performed with a sensitivity of 80.4% (95% CI: 69.5-91.3), specificity of 98.0% (95% CI: 97.1-98.9), positive predictive value of 69.5% (95% CI: 57.7-81.2), negative predictive value of 98.9% (95% CI: 98.2% to 99.6%) and kappa statistic of 0.73 (95% CI: 0.63-0.83).
Conclusion: Using a combination of hospital discharge abstracts and physician bill- ing data may be the best way of assessing trends of MI occurrence over time since it increases the capture of MI beyond those patients who have been hospitalized.
SUMMARY
Purpose: To determine the validity of pregnancy variables recorded in administrative databases of Quebec using patient medical charts as the gold standard among asthmatic pregnant women.
Methods: Three administrative databases were linked and provided information on maternal, pregnancy and infant characteristics for 726 pregnant asthmatic women who delivered in 1990–2000. Algorithms were developed to measure variables that were not recorded directly in the databases or to minimize the number of missing values for variables recorded in two or more databases. Medical file data were collected by two trained research nurses in 43 hospitals. The validity of categorical variables was assessed with sensitivity, specificity, predictive positive values (PPVs) and predictive negative values (PNVs), whereas the validity of continuous variables was assessed with Pearson correlation using the medical chart as the gold standard.
Results: The sensitivity of the sex of the baby, previous live birth and previous pregnancy ranged from 0.97 to 0.99. Corresponding figures were 0.92–0.98 for specificity. We also found high correlation coefficients, ranging from 0.875 to 0.999 for the length of gestation, dates of last menstruation and delivery, maternal age and birth weight.
Conclusion: Pregnancy-related variables recorded in administrative databases or derived from algorithms based on two or more databases were found to be highly valid as compared to the medical chart among asthmatic women.
key words — validation; pregnancy-related variables; administrative databases; medical chart; asthma
Objective. To assess the association between the initiation of anti–tumor necrosis factor (anti-TNF) therapy and the risk of serious bacterial infections in routine care.
Methods. This was a cohort study of patients with rheumatoid arthritis (RA) in whom specific disease- modifying antirheumatic drugs (DMARDs) were initiated. Patients were Medicare beneficiaries ages 65 years and older (mean age 76.5 years) who were concurrently enrolled in the Pharmaceutical Assistance Contract for the Elderly provided by the state of Pennsylvania. A total of 15,597 RA patients in whom a DMARD was initiated between January 1, 1995 and December 31, 2003 were identified using linked data on all prescription drug dispensings, physician services, and hospitalizations. Initiation of anti-TNF therapy, cytotoxic agents other than methotrexate (MTX), noncytotoxic agents, and glucocorticoids was compared with initia- tion of MTX. The main outcome measure was serious bacterial infections that required hospitalization.
Objective. To develop the Self-Administered Comorbidity Questionnaire (SCQ) and assess its psychometric properties, including the predictive validity of the instrument, as reflected by its association with health status and health care utilization after 1 year.
Methods. A cross-sectional comparison of the SCQ with a standard, chart abstraction-based measure (Charlson Index) was conducted on 170 inpatients from medical and surgical care units. The association of the SCQ with the chart-based comorbidity instrument and health status (short form 36) was evaluated cross sectionally. The association between these measures and health status and resource utilization was assessed after 1 year.
Results. The Spearman correlation coefficient for the association between the SCQ and the Charlson Index was 0.32. After restricting each measure to include only comparable items, the correlation between measures was stronger (Spearman r
Rheumatoid arthritis (RA) is often characterized by the burden of swollen joints, pain, and de- creased physical function, but less understood are the many manifestations of additional health conditions that are associated with RA and its treatments. First brought to light with observations of increased mortality in RA, studies noted the increased rates of cardiovascular and infection events. The chronic, debilitating, autoimmune nature of RA affects the patient directly or indi rectly in almost all organ systems, from cardiovascular problems and infections to depression and gastrointestinal ulcers. On average, the established RA patient has two or more comorbid conditions. It should be the responsibility of the rheumatologist to take these and the risk of additional conditions into account when treating the patient. This chapter reviews important comorbidities in patients with RA, their prevalence, and their relation to RA.
Key words: anti-TNF therapy; cardiovascular disease; comorbid condition; comorbidity index; comorbidity; infection; malignancy; outcomes; rheumatoid arthritis.
