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Vijaya Sundararajan

Publications and source records attributed to Vijaya Sundararajan.

At least 19 recordsLinked to original sources
PubMed2006

Identifying priorities in methodological research using ICD-9-CM and ICD-10 administrative data: report from an international consortium.

BACKGROUND: Health administrative data are frequently used for health services and population health research. Comparative research using these data has been facilitated by the use of a standard system for coding diagnoses, the International Classification of Diseases (ICD). Research using the data must deal with data quality and validity limitations which arise because the data are not created for research purposes. This paper presents a list of high-priority methodological areas for researchers using health administrative data. METHODS: A group of researchers and users of health administrative data from Canada, the United States, Switzerland, Australia, China and the United Kingdom came together in June 2005 in Banff, Canada to discuss and identify high-priority methodological research areas. The generation of ideas for research focussed not only on matters relating to the use of administrative data in health services and population health research, but also on the challenges created in transitioning from ICD-9 to ICD-10. After the brain-storming session, voting took place to rank-order the suggested projects. Participants were asked to rate the importance of each project from 1 (low priority) to 10 (high priority). Average ranks were computed to prioritise the projects. RESULTS: Thirteen potential areas of research were identified, some of which represented preparatory work rather than research per se. The three most highly ranked priorities were the documentation of data fields in each country's hospital administrative data (average score 8.4), the translation of patient safety indicators from ICD-9 to ICD-10 (average score 8.0), and the development and validation of algorithms to verify the logic and internal consistency of coding in hospital abstract data (average score 7.0). CONCLUSION: The group discussions resulted in a list of expert views on critical international priorities for future methodological research relating to health administrative data. The consortium's members welcome contacts from investigators involved in research using health administrative data, especially in cross-jurisdictional collaborative studies or in studies that illustrate the application of ICD-10.

Algorithms↗
PubMed2006

Quality of diagnosis and procedure coding in ICD-10 administrative data.

OBJECTIVES: The International Classification of Disease, 10th Revision (ICD-10) was introduced worldwide beginning in the late 1990s. Because there have been no published data on the quality of coding using ICD-10, the aim of our analysis is to assess the quality of ICD-10 coding in routinely collected hospital discharge data from Australia, which began using ICD-10 in 1998. METHODS: Audit data from the years 1998-1999 (n = 7004) and 2000-2001 (n = 7631), excluding same-day chemotherapy and dialysis cases, were used in data analysis. Quality measures included prevalence comparisons, sensitivity, positive predictive value (PPV), and the kappa statistic. RESULTS: Comparison of the audit sample to public hospital discharges showed little difference in age and gender, with audited cases more likely to be overnight stays. There was no difference in the median number of hospital assigned diagnosis and procedure codes per discharge. Agreement of the principal diagnosis code was 85% at the 3-digit level and 79% at the 4-digit level in 1998-1999; this rate had improved to 87% and 81% in 2000-2001. Principal procedure code agreement was 85% in 1998-1999 and 83% in 2000-2001 at the 5-digit level, and 81% and 80% at the 7-digit level, respectively. Specific major diagnoses, comorbid diagnoses, major procedures, and minor procedures showed good-to-excellent coding quality. CONCLUSIONS: The transition to ICD-10 has occurred with no loss of data quality, with data showing a high level of reliability and adherence to coding standards. When consideration is given to the nature of the analysis, administrative data can provide highly reliable population-based estimates of hospitalization rates.

Adult↗
PubMed2006

A comparison of data sources for the surveillance of seasonal and pandemic influenza in Victoria.

Understanding the characteristics of available influenza or influenza-like illness (ILI) surveillance systems is important for seasonal influenza surveillance and pandemic preparedness. We compared five influenza or ILI data sources in Victoria: notifications of laboratory-confirmed influenza to the Victorian Department of Human Services; hospital emergency presentations and hospital admissions; sentinel general practitioner surveillance; and medical locum service surveillance. Seasonal trends for influenza and ILI activity were similar for all data sources. Community ILI surveillance, operating as sentinel GP, locum service or hospital emergency department surveillance, in conjunction with notification of laboratory-confirmed influenza, would provide adequate inter-pandemic surveillance for influenza in Victoria and, by extension, in any Australian jurisdiction. Other surveillance systems would be needed for early pandemic case or cluster detection, while pandemic monitoring would be better achieved by a more automated system.

Adolescent↗
PubMed2005

Effect of an on-site emergency physician in a rural emergency department at night.

INTRODUCTION: The problem of emergency department (ED) overcrowding is an issue of some concern and staffing profile has been identified as a contributing factor. The aim of this study was to assess the effect of having an emergency physician on-site at night in a rural base hospital ED in terms of the ED length of stay, waiting times, admissions, specialist consultations, the use of diagnostic tests, and ED representations within 7 days. METHODS: A retrospective analysis was performed of the ED database at Tamworth Base Hospital in rural New South Wales, Australia. A comparison was made between 125 patients seen when an emergency physician was in the department (Group A) and 117 patients seen when an emergency physician was not on site (Group B). RESULTS: The mean ED length of stay was 48 min for Group A and 96 min for Group B. There were 15 admissions from Group A and 27 from Group B. There were significantly less pathology tests and consultations for the patients in Group A compared with Group B. There was no significant difference in waiting times or in the re-presentation rate between the two groups. CONCLUSIONS: The presence of an on-site emergency physician resulted in a significantly shorter ED length of stay, lower admission rate, less initial pathology tests, and fewer telephone consultations.

Adult↗
PubMed2005

Epidemiology of sepsis in Victoria, Australia.

OBJECTIVE: To determine the clinical and epidemiologic characteristics of patients with sepsis admitted to hospitals in Victoria, Australia, including the incidence of sepsis and severe sepsis, utilization of intensive care unit (ICU) resources, and hospital mortality. DESIGN: A population-based hospital morbidity database generated from hospital discharge coding. SETTING: State of Victoria, Australia (population, 4.5 million), the 4-yr period from July 1, 1999, to June 30, 2003. PATIENTS: A total of 3,122,515 overnight hospitalizations. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The overall hospital incidence of sepsis was 1.1%, with a mortality of 18.4%. Of septic patients, 23.8% received some care in an ICU. For these patients, hospital mortality was 28.9%. Severe sepsis, defined by sepsis and at least one organ dysfunction, occurred in 39% of sepsis patients and was accompanied by a hospital mortality of 31.1%. Fifty percent of patients with severe sepsis received at least some care in an ICU. CONCLUSIONS: Australian state hospital administrative data reveal epidemiologic features of sepsis and severe sepsis that are strikingly similar to those recently reported from comparable populations in North American and Europe. This suggests that lessons learned in this area may be directly applicable internationally.

Adolescent↗
PubMed2005

Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data.

OBJECTIVES: Implementation of the International Statistical Classification of Disease and Related Health Problems, 10th Revision (ICD-10) coding system presents challenges for using administrative data. Recognizing this, we conducted a multistep process to develop ICD-10 coding algorithms to define Charlson and Elixhauser comorbidities in administrative data and assess the performance of the resulting algorithms. METHODS: ICD-10 coding algorithms were developed by "translation" of the ICD-9-CM codes constituting Deyo's (for Charlson comorbidities) and Elixhauser's coding algorithms and by physicians' assessment of the face-validity of selected ICD-10 codes. The process of carefully developing ICD-10 algorithms also produced modified and enhanced ICD-9-CM coding algorithms for the Charlson and Elixhauser comorbidities. We then used data on in-patients aged 18 years and older in ICD-9-CM and ICD-10 administrative hospital discharge data from a Canadian health region to assess the comorbidity frequencies and mortality prediction achieved by the original ICD-9-CM algorithms, the enhanced ICD-9-CM algorithms, and the new ICD-10 coding algorithms. RESULTS: Among 56,585 patients in the ICD-9-CM data and 58,805 patients in the ICD-10 data, frequencies of the 17 Charlson comorbidities and the 30 Elixhauser comorbidities remained generally similar across algorithms. The new ICD-10 and enhanced ICD-9-CM coding algorithms either matched or outperformed the original Deyo and Elixhauser ICD-9-CM coding algorithms in predicting in-hospital mortality. The C-statistic was 0.842 for Deyo's ICD-9-CM coding algorithm, 0.860 for the ICD-10 coding algorithm, and 0.859 for the enhanced ICD-9-CM coding algorithm, 0.868 for the original Elixhauser ICD-9-CM coding algorithm, 0.870 for the ICD-10 coding algorithm and 0.878 for the enhanced ICD-9-CM coding algorithm. CONCLUSIONS: These newly developed ICD-10 and ICD-9-CM comorbidity coding algorithms produce similar estimates of comorbidity prevalence in administrative data, and may outperform existing ICD-9-CM coding algorithms.

Algorithms↗
PubMed2004

Effects of increased private health insurance on hospital utilisation in Victoria.

The proportion of Victorians and Australians generally with private health insurance (PHI) increased from 31% in 1998 to 45% in 2001. We analysed a dataset containing all hospital separations throughout Victoria to determine whether changes in the level of private health insurance have had any impact on patterns of public and private hospital utilisation in Victoria. Total utilisation of private hospitals grew by 31% from 1998-99 to 2002-03, whereas utilisation of public hospitals increased by 18%. Total bed-days have increased in both private hospitals and public hospitals by 12%. The proportion of all separations at private hospitals has remained relatively stable between these 2 years, with 33% of all separations being private patients in private hospitals in 1998-99, increasing slightly to 35% by 2002-03. Analysis of a number of specific DRGs shows that patients with more severe disease are more likely to be seen at public hospitals; notably this trend has strengthened between 1998-99 and 2002-03. The number of patients treated in Victorian public hospitals has continued to grow, despite a rapid increase in the utilisation of private hospitals. Given the limited extent of the shift in caseload share between the two sectors, the effectiveness of the Commonwealth's subsidy of private health insurance as a mechanism to reduce pressure on the public sector needs to be carefully examined.

Adolescent↗
PubMed2004

Attendance rates and outcomes of cardiac rehabilitation in Victoria, 1998.

OBJECTIVE: To describe the patterns of use of cardiac rehabilitation in Victoria and to assess whether the survival benefits predicted in clinical trials have been realised in the community. DESIGN: Cohort study based on data linkage. PARTICIPANTS: All patients admitted for acute myocardial infarction (AMI), coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA) in Victoria in 1998 (n = 12821). INTERVENTIONS: Attendance at one of 66 participating outpatient cardiac rehabilitation centres in Victoria. MAIN OUTCOME MEASURES: Rates of attendance at rehabilitation based on key factors such as diagnosis, age, sex, and comorbidity. Five-year survival for attendees compared with non-attendees. RESULTS: Rates of participation in rehabilitation were 15% for AMI, 37% for CABG, and 14% for PTCA. Rehabilitation attendance rates dropped sharply after 70 years of age. Attendees had a 35% improvement in 5-year survival (hazard ratio for death associated with rehabilitation attendance, 0.65 [95% CI, 0.56-0.75]). CONCLUSIONS: Attendance rates at cardiac rehabilitation are suboptimal, even though attendance confers a clinically significant difference in 5-year survival. The elderly, women, and those with comorbid conditions may benefit measurably from increased rates of attendance.

Adult↗
PubMed2004

New ICD-10 version of the Charlson comorbidity index predicted in-hospital mortality.

BACKGROUND AND OBJECTIVE: The ICD-9-CM adaptation of the Charlson comorbidity score has been a valuable resource for health services researchers. With the transition into ICD-10 coding worldwide, an ICD-10 version of the Deyo adaptation was developed and validated using population-based hospital data from Victoria, Australia. METHODS: The algorithm was translated from ICD-9-CM into ICD-10-AM (Australian modification) in a multistep process. After a mapping algorithm was used to develop an initial translation, these codes were manually examined by the coding experts and a general physician for face validity. Because the ICD-10 system is country specific, our goal was to keep many of the translated code at the three-digit level for generalizability of the new index. RESULTS: There appears to be little difference in the distribution of the Charlson Index score between the two versions. A strong association between increasing index scores and mortality exists: the area under the ROC curve is 0.865 for the last year using the ICD-9-CM version and remains high, at 0.855, for the ICD-10 version. CONCLUSION: This work represents the first rigorous adaptation of the Charlson comorbidity index for use with ICD-10 data. In comparison with a well-established ICD-9-CM coding algorithm, it yields closely similar prevalence and prognosis information by comorbidity category.

Algorithms↗
PubMed2004

Patterns and outcomes of chemotherapy for elderly patients with stage II ovarian cancer: a population-based study.

BACKGROUND: The optimal treatment for patients with stage II ovarian cancer is controversial, although most experts recommend adjuvant chemotherapy. The purpose of this study was to assess the patterns of use of chemotherapy in women with stage II ovarian cancer, and to compare the survival of treated and untreated patients aged 65+ years in a population-based sample. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database of cancers diagnosed in approximately 14% of the U.S. population, we identified women who were diagnosed with stage II ovarian cancer between 1992 and 1996, survived >or=120 days beyond diagnosis, and were >or=65 years of age. Multivariate regression was used to compare those treated to those not treated with chemotherapy. Cox proportional hazards regression models were used to analyze patient survival. RESULTS: Of 236 women with stage II ovarian cancer, 160 (67.8%) received chemotherapy, and 118 (50%) received platinum-based regimens. Younger patients and those with higher-grade tumors were more likely to receive chemotherapy. The adjusted hazards ratio for mortality associated with any chemotherapy use was 0.67 (95% CI, 0.45-0.98), corresponding to an increase in median survival from 28 months to 35 months (P < 0.0001). CONCLUSIONS: This observational study found that most patients aged >or=65 years and diagnosed with stage II ovarian cancer between 1992 and 1996 were treated with chemotherapy. Grade and younger age were the most significant predictors of treatment, and treatment was associated with a 5-year mortality reduction of 33%. These findings are not definitive, but they may provide some guidance in the absence of randomized trials of adjuvant chemotherapy for older women with stage II ovarian cancer.

Aged↗
PubMed2004

Effectiveness of platinum-based chemotherapy among elderly patients with advanced ovarian cancer.

BACKGROUND: Platinum-based chemotherapy is the standard of care for women with advanced ovarian cancer based on the results of randomized trials. We previously showed that only about half of women over the age of 65 years with this disease received platinum-based chemotherapy, and that the likelihood of receiving it decreases with age. METHODS: We used the Surveillance, Epidemiology, and End Results (SEER)-Medicare database to identify women diagnosed from 1/1/92 to 12/31/96 with stage III or IV ovarian cancer who survived > or =120 days beyond diagnosis, and were > or =65 years of age. Cox proportional hazards models and propensity scores were used to control for known predictors of receiving treatment and to estimate the relative effectiveness of different platinum-based regimens. RESULTS: Of the 1759 patients in the sample who met our eligibility criteria, 53% received platinum-based therapy. For this sample, the Cox proportional hazard ratio was 0.72 (95% CI, 0.62-0.91) for mortality associated with the use of any platinum-based therapy, and 0.59 (95% CI, 0.45-0.76) for combination platinum/paclitaxel therapy. Similar results were obtained using propensity score modeling. CONCLUSIONS: In this population-based study, we found that only about half of women with advanced ovarian cancer over age 65 were treated with platinum-based chemotherapy; however, survival improved by 38% in treated women, similar to the benefits described in randomized controlled trials among younger patients, and were greatest when platinum was combined with paclitaxel. An effort to increase the utilization of platinum combination therapy among older patients with advanced ovarian cancer is justified.

Aged↗
PubMed2004

Ethnic and cultural determinants influence risk assessment for hepatitis C acquisition.

BACKGROUND AND AIM: In the developed world hepatitis C virus (HCV) infection is predominantly associated with sharing contaminated equipment between injecting drug users (IDU). In developing countries inadequately sterilized medical equipment, transmission of infected blood and cultural practices have been implicated. Accurate risk factor assessment is essential for education targeted at risk reduction in culturally diverse populations. METHODS: Ninety Australian-born Caucasians and 72 South-east Asian (SEA) HCV patients attending a Melbourne hospital liver clinic completed a questionnaire which assessed risk factor profile, perceived risk factors, knowledge of risk factors and methods to minimize transmission. Medical records were audited to identify doctor assessment of risk factors. RESULTS: Risk factors in Caucasians were IDU, body piercing and tattooing (89%, 47% and 32%, respectively). Risk factors in SEA patients were injection therapy, dental therapy and surgery (89%, 70% and 38%, respectively). Most Caucasian patients (94%) correctly identified their mode of acquisition compared with 33% of SEA patients (P < 0.0001). Accurate risk factor documentation in medical records was more common in Caucasians (96 vs 32%; P < 0.0001). The majority of patients identified blood-to-blood and sexual/vertical transmission as important modes of acquisition. However, 33% of SEA patients believed transmission occurred through food, water and poor hygiene and 80% did not identify therapeutic injection or traditional medical practices as risk factors. Education provided to SEA patients did not address less well established routes of transmission. CONCLUSIONS: Ethnicity influences perception and knowledge of risk factors. Improved assessment of risk factors in high-risk ethnic groups is needed. Education should be culturally appropriate and address the concerns of all populations with HCV.

Adolescent↗
PubMed2004

Management of colorectal cancer in elderly patients: focus on the cost of chemotherapy.

The treatment of colorectal cancer has evolved dramatically over the last 15 years. Advances in surgery, radiotherapy and chemotherapy have enabled oncologists to cure more patients and offer improved quality of life to patients not amenable to cure. Specific knowledge of colorectal cancer care of the elderly, while lagging behind the treatment of younger patients, is beginning to emerge. Informed by recent trials, the approach towards elderly patients is shifting towards more aggressive treatment and multimodal therapy. Surgeons are operating on the elderly with greater frequency, less operative mortality and greater success; 5-year survival following potentially curative surgery has risen from 50% to 67%.Research of adjunctive therapy for colorectal cancer is enrolling more elderly patients, and with this has come an understanding of the role of chemotherapeutic agents in the treatment of the elderly, used individually and within multi-drug regimens. This research offers insight into how the elderly respond to chemotherapy, informing clinicians on anticipated benefits and toxicities of treatment. Fluorouracil-based regimens, which have long been the standard adjuvant chemotherapy, have been shown to offer benefits to the elderly compared with those not receiving adjuvant chemotherapy (71% versus 64% 5-year survival), and to cause similar toxicities as seen in younger patients. The role of novel chemotherapeutic agents in the treatment of elderly patients with colorectal cancer is also emerging, with studies finding that irinotecan, in combination with a fluorouracil-based regimen, can offer a further survival benefit of over 2 months compared with fluorouracil alone. While newer agents such as capecitabine, oxaliplatin, raltitrexed and tegafur/uracil (UFT) have been focused upon by clinical researchers, data on their use in the elderly remain unconvincing. Not only are we approaching a clearer understanding of the effectiveness of cancer care among the elderly, but research is also beginning to identify the cost effectiveness of both standard and emerging chemotherapeutic agents. Cost effectiveness of fluorouracil-based regimens, depending on delivery strategy, use of modulating agents and stage of cancer vary from US dollars 2000 per quality-adjusted life-year (QALY) to US dollars 20200 per QALY (1992 values). Irinotecan therapy has not been fully investigated from the perspective of cost effectiveness; the figure of US dollars 10000 per QALY (1998 values) for irinotecan monotherapy over fluorouracil regimens is likely an underestimate, while cost analysis of irinotecan and fluorouracil combination therapy has not yet been reported. Our understanding of cost effectiveness of other novel agents has lagged behind; further research on these agents is needed. Nonetheless, as the effects of these novel agents upon both outcomes and costs continue to be defined, both curative and palliative treatment of colorectal cancer in the elderly patient will become more sophisticated and effective.

Aged↗
PubMed2003

Risk of perforation after colonoscopy and sigmoidoscopy: a population-based study.

BACKGROUND: Although the risk of bowel perforation is often cited as a major factor in the choice between colonoscopy and sigmoidoscopy for colorectal screening, good estimates of the absolute and relative risks of perforation are lacking. METHODS: We used a large population-based cohort that consisted of a random sample of 5% of Medicare beneficiaries living in regions of the United States covered by the Surveillance, Epidemiology, and End Results (SEER) Program registries to determine rates of perforation in people aged 65 years and older. We identified individuals who were cancer-free and had undergone colonoscopy or sigmoidoscopy between 1991 and 1998, calculated both the incidence and risk of perforation within 7 days of the procedure, and explored the impact on incidence and risk of perforation of age, race/ethnicity, sex, comorbidities, and indication for the procedure. We also estimated the risk of death after perforation. Risks were calculated with odds ratios (ORs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: There were 77 perforations after 39 286 colonoscopies (incidence = 1.96/1000 procedures) and 31 perforations after 35 298 sigmoidoscopies (incidence = 0.88/1000 procedures). After adjustment, the OR for perforation from colonoscopy relative to perforation from sigmoidoscopy was 1.8 (95% CI = 1.2 to 2.8). Risk of perforation from either procedure increased in association with increasing age (P(trend)<.001 for both procedures) and the presence of two or more comorbidities (P(trend)<.001 for colonoscopy and P(trend) =.03 for sigmoidoscopy). Compared with those who were endoscopied and did not have a perforation, the risk of death was statistically significantly increased for those who had a perforation after either colonoscopy (OR = 9.0, 95% CI = 3.0 to 27.3) or sigmoidoscopy (OR = 8.8, 95% CI = 1.6 to 48.5). The risk of perforation after colonoscopy, especially for screening procedures, declined during the 8-year study period. CONCLUSIONS: The risk of perforation after colonoscopy is approximately double that after sigmoidoscopy, but this difference appears to be decreasing. These observations should be useful to clinicians making screening and diagnostic decisions for individual patients and to policy officials setting guidelines for colorectal cancer screening programs.

Aged↗
PubMed2003

Respiratory tract infections in travelers: a review of the GeoSentinel surveillance network.

Respiratory tract infections are common in travelers, and improving our knowledge of risk factors associated with specific types of respiratory infections should enable implementation of better preventive strategies. Data collected by the GeoSentinel surveillance network were analyzed, and the most significant predictors for developing specific categories of respiratory infections while abroad were age, sex, season of travel, trip duration, and reason for travel. In particular, influenza was associated with travel to the Northern Hemisphere during the period of December through February, travel involving visits to friends or relatives, and trip duration of >30 days. Lower respiratory tract infections were associated with male sex and increasing age. Knowledge of the respiratory tract infections that occur in specific groups of travelers allows for the development of targeted pretravel preventive strategies to high-risk groups.

Adolescent↗
PubMed2003

The effect of increased private health insurance coverage on Victorian public hospitals.

It was anticipated that the recent reforms to private health insurance arrangements would reduce the demand pressures on Australian public hospitals. However, this has not been demonstrated by trends in elective surgery waiting lists in Victorian public hospitals. Moreover, it appears that the increased caseload assumed by Victorian private hospitals since the reforms took effect mainly reflects an increase in low cost same day episodes.

Elective Surgical Procedures↗
PubMed2003

Novel biomedical risk markers for cardiovascular disease.

Molecular moieties within newly discovered pathophysiological pathways in atherothrombosis represent potential biomedical risk markers for cardiovascular disease. Their discovery is important in that a large proportion of cardiovascular disease is unexplained by 'conventional' risk markers, and that novel markers may pave the way to new targets for intervention. Many candidate markers have been identified, among which inflammatory and haemostatic factors are prominent. This review will examine the evidence for the roles of key novel risk markers in cardiovascular disease, against criteria which define causality as well as potential clinical utility.

Biomarkers↗