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Hude Quan

Publications and source records attributed to Hude Quan.

At least 19 recordsLinked to original sources
PubMed2006

ICD-10 coding algorithms for defining comorbidities of acute myocardial infarction.

BACKGROUND: With the introduction of ICD-10 throughout Canada, it is important to ensure that Acute Myocardial Infarction (AMI) comorbidities employed in risk adjustment methods remain valid and robust. Therefore, we developed ICD-10 coding algorithms for nine AMI comorbidities, examined the validity of the ICD-10 and ICD-9 coding algorithms in detection of these comorbidities, and assessed their performance in predicting mortality. The nine comorbidities that we examined were shock, diabetes with complications, congestive heart failure, cancer, cerebrovascular disease, pulmonary edema, acute renal failure, chronic renal failure, and cardiac dysrhythmias. METHODS: Coders generated a comprehensive list of ICD-10 codes corresponding to each AMI comorbidity. Physicians independently reviewed and determined the clinical relevance of each item on the list. To ensure that the newly developed ICD-10 coding algorithms were valid in recording comorbidities, medical charts were reviewed. After assessing ICD-10 algorithms' validity, both ICD-10 and ICD-9 algorithms were applied to a Canadian provincial hospital discharge database to predict in-hospital, 30-day, and 1-year mortality. RESULTS: Compared to chart review data as a 'criterion standard', ICD-9 and ICD-10 data had similar sensitivities (ranging from 7.1-100%), and specificities (above 93.6%) for each of the nine AMI comorbidities studied. The frequencies for the comorbidities were similar between ICD-9 and ICD-10 coding algorithms for 49,861 AMI patients in a Canadian province during 1994-2004. The C-statistics for predicting 30-day and 1 year mortality were the same for ICD-9 (0.82) and for ICD-10 data (0.81). CONCLUSION: The ICD-10 coding algorithms developed in this study to define AMI comorbidities performed similarly as past ICD-9 coding algorithms in detecting conditions and risk-adjustment in our sample. However, the ICD-10 coding algorithms should be further validated in external databases.

Adult↗
PubMed2006

Dealing with missing data in a multi-question depression scale: a comparison of imputation methods.

BACKGROUND: Missing data present a challenge to many research projects. The problem is often pronounced in studies utilizing self-report scales, and literature addressing different strategies for dealing with missing data in such circumstances is scarce. The objective of this study was to compare six different imputation techniques for dealing with missing data in the Zung Self-reported Depression scale (SDS). METHODS: 1580 participants from a surgical outcomes study completed the SDS. The SDS is a 20 question scale that respondents complete by circling a value of 1 to 4 for each question. The sum of the responses is calculated and respondents are classified as exhibiting depressive symptoms when their total score is over 40. Missing values were simulated by randomly selecting questions whose values were then deleted (a missing completely at random simulation). Additionally, a missing at random and missing not at random simulation were completed. Six imputation methods were then considered; 1) multiple imputation, 2) single regression, 3) individual mean, 4) overall mean, 5) participant's preceding response, and 6) random selection of a value from 1 to 4. For each method, the imputed mean SDS score and standard deviation were compared to the population statistics. The Spearman correlation coefficient, percent misclassified and the Kappa statistic were also calculated. RESULTS: When 10% of values are missing, all the imputation methods except random selection produce Kappa statistics greater than 0.80 indicating 'near perfect' agreement. MI produces the most valid imputed values with a high Kappa statistic (0.89), although both single regression and individual mean imputation also produced favorable results. As the percent of missing information increased to 30%, or when unbalanced missing data were introduced, MI maintained a high Kappa statistic. The individual mean and single regression method produced Kappas in the 'substantial agreement' range (0.76 and 0.74 respectively). CONCLUSION: Multiple imputation is the most accurate method for dealing with missing data in most of the missind data scenarios we assessed for the SDS. Imputing the individual's mean is also an appropriate and simple method for dealing with missing data that may be more interpretable to the majority of medical readers. Researchers should consider conducting methodological assessments such as this one when confronted with missing data. The optimal method should balance validity, ease of interpretability for readers, and analysis expertise of the research team.

Alberta↗
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

Assessing record linkage between health care and Vital Statistics databases using deterministic methods.

BACKGROUND: We assessed the linkage and correct linkage rate using deterministic record linkage among three commonly used Canadian databases, namely, the population registry, hospital discharge data and Vital Statistics registry. METHODS: Three combinations of four personal identifiers (surname, first name, sex and date of birth) were used to determine the optimal combination. The correct linkage rate was assessed using a unique personal health number available in all three databases. RESULTS: Among the three combinations, the combination of surname, sex, and date of birth had the highest linkage rate of 88.0% and 93.1%, and the second highest correct linkage rate of 96.9% and 98.9% between the population registry and Vital Statistics registry, and between the hospital discharge data and Vital Statistics registry in 2001, respectively. Adding the first name to the combination of the three identifiers above increased correct linkage by less than 1%, but at the cost of lowering the linkage rate almost by 10%. CONCLUSION: Our findings suggest that the combination of surname, sex and date of birth appears to be optimal using deterministic linkage. The linkage and correct linkage rates appear to vary by age and the type of database, but not by sex.

Adolescent↗
PubMed2006

Variation in health services utilization among ethnic populations.

BACKGROUND: Although racial and ethnic disparities in health services utilization and outcomes have been extensively studied in several countries, this issue has received little attention in Canada. We therefore analyzed data from the 2001 Canadian Community Health Survey to compare the use of health services by members of visible minority groups and nonmembers (white people) in Canada. METHODS: Logistic regression was used to compare physician contacts and hospital admissions during the 12 months before the survey and recent cancer screening tests. Explanatory variables recorded from the survey included visible minority status, sociodemographic factors and health measures. RESULTS: Respondents included 7057 members of visible minorities and 114,255 white people for analysis. After adjustments for sociodemographic and health characteristics, we found that minority members were more likely than white people to have had contact with a general practitioner (adjusted odds ratio [OR] 1.28, 95% confidence interval [CI] 1.14-1.42), but not specialist physicians (OR 1.01, 95% CI 0.93-1.10). Members of visible minorities were less likely to have been admitted to hospital (OR 0.83, 95% CI 0.70- 0.98), tested for prostate-specific antigen (OR 0.64, 95% CI 0.52-0.79), administered a mammogram (OR 0.68, 95% CI 0.59-0.80) or given a Pap test (OR 0.47, 95% CI 0.39-0.56). INTERPRETATION: Use of health services in Canada varies considerably by ethnicity according to type of service. Although there is no evidence that members of visible minorities use general physician and specialist services less often than white people, their utilization of hospital and cancer screening services is significantly less.

Adolescent↗
PubMed2006

Location of residence associated with the likelihood of patient visit to the preoperative assessment clinic.

BACKGROUND: Outpatient preoperative assessment clinics were developed to provide an efficient assessment of surgical patients prior to surgery, and have demonstrated benefits to patients and the health care system. However, the centralization of preoperative assessment clinics may introduce geographical barriers to utilization that are dependent on where a patient lives with respect to the location of the preoperative assessment clinic. METHODS: The association between geographical distance from a patient's place of residence to the preoperative assessment clinic, and the likelihood of a patient visit to the clinic prior to surgery, was assessed for all patients undergoing surgery at a tertiary health care centre in a major Canadian city. The odds of attending the preoperative clinic were adjusted for patient characteristics and clinical factors. RESULTS: Patients were less likely to visit the preoperative assessment clinic prior to surgery as distance from the patient's place of residence to the clinic increased (adjusted OR = 0.52, 95% CI 0.44-0.63 for distances between 50-100 km, and OR = 0.26, 95% CI 0.21-0.31 for distances greater than 250 km). This 'distance decay' effect was remarkable for all surgical specialties. CONCLUSION: The present study demonstrates that the likelihood of a patient visiting the preoperative assessment clinic appears to depend on the geographical location of patients' residences. Patients who live closest to the clinic tend to be seen more often than patients who live in rural and remote areas. This observation may have implications for achieving the goals of equitable access, and optimal patient care and resource utilization in a single universal insurer health care system.

Adult↗
PubMed2006

Development and validation of a surname list to define Chinese ethnicity.

OBJECTIVE: Surnames have the potential to accurately identify ancestral origins as they are passed on from generation to generation. In this study, we developed and validated a Chinese surname list to define Chinese ethnicity. METHODS: We conducted a literature review, a panel review, and a telephone survey in a randomly selected sample from a Canadian city in 2003 to develop a Chinese surname list. The list was then validated to data from the Canadian Community Health Survey. Both surveys collected information on self-reported ethnicity and surname. RESULTS: Of the 112,452 people analyzed in the Canadian Community Health Survey, 1.6% were self-reported as Chinese. This was similar to the 1.5% identified by the surname list. Compared with self-reported Chinese ethnicity (reference standard), the surname list had 77.7% sensitivity, 80.5% positive predictive value, 99.7% specificity, and 99.6% negative predictive value. When stratifying by sex and marital status, the positive predictive value was 78.9% for married women and 83.6% for never married women. CONCLUSIONS: The Chinese surname list appears to be valid in identifying Chinese ethnicity. The validity may depend on the geographic origins and Chinese dialects in given populations.

Adolescent↗
PubMed2006

Association of postoperative complications with hospital costs and length of stay in a tertiary care center.

BACKGROUND: Postoperative complications are a significant source of morbidity and mortality. There are limited studies, however, assessing the impact of common postoperative complications on health care resource utilization. OBJECTIVE: To assess the association of clinically important postoperative complications with total hospital costs and length of stay (LOS) in patients undergoing noncardiac surgery. METHODS: We determined total hospital costs and LOS in all patients admitted to a single tertiary care center between July 1, 1996 and March 31, 1998 using a detailed administrative hospital discharge database. Total hospital costs and LOS were adjusted for preoperative and surgical characteristics. RESULTS: Of 7,457 patients who underwent noncardiac surgery, 6.9% developed at least 1 of the postoperative complications. These complications increased hospital costs by 78% (95% confidence interval [CI]: 68% to 90%) and LOS by 114% (95% CI: 100% to 130%) after adjustment for patient preoperative and surgical characteristics. Postoperative pneumonia was the most common complication (3%) and was associated with a 55% increase in hospital costs (95% CI: 42% to 69%) and an 89% increase in LOS (95% CI: 70% to 109%). CONCLUSIONS: Postoperative complications consume considerable health care resources. Initiatives targeting prevention of these events could significantly reduce overall costs of care and improve patient quality of care.

Adult↗
PubMed2005

Statins are associated with better outcomes after carotid endarterectomy in symptomatic patients.

BACKGROUND AND PURPOSE: Statins have been associated with a reduction in mortality from noncardiac surgery. This study aimed to determine whether statin use on admission to hospital for carotid endarterectomy was associated with a reduction of in-hospital adverse outcomes. METHODS: Data describing patient characteristics, surgical indication, statin treatment, and in-hospital outcomes of death, ischemic stroke or death and cardiac outcomes were collected from a chart review of all patients (3360) undergoing carotid endarterectomy in Western Canada from January 2000 to December 2001. Outcomes of patients on statins versus those not on statins were compared using logistic regression to account for differences in patient characteristics, and propensity score methods to account for factors influencing patient allocation to statins. RESULTS: Eight hundred and fifteen of 2031 symptomatic patients and 665 of 1252 asymptomatic patients were on a statin at the time of hospital admission. Statin use by symptomatic patients was associated with reduced in-hospital mortality and in-hospital ischemic stroke or death, but not in-hospital cardiac outcomes (adjusted odds ratio 0.25 [CI, 0.07 to 0.90], 0.55 [CI, 0.32 to 0.95], 0.87 [CI, 0.49 to 1.54], respectively). The improvement in outcomes was robust when tested using propensity score matching. This association was not seen in asymptomatic patients on statins (adjusted odds ratio, in-hospital mortality 0.54 [CI, 0.13 to 2.24]; in-hospital ischemic stroke or death 1.34 [CI, 0.61 to 2.93]; in-hospital cardiac outcomes 1.37 [CI, 0.73 to 2.58]). CONCLUSIONS: These findings are suggestive of a protective effect of statin therapy in symptomatic patients pre-treated at the time of carotid endarterectomy, though this needs confirmation in a randomized controlled trial.

Aged↗
PubMed2005

Association between physician specialty and volumes of treated patients and mortality among patients hospitalized for newly diagnosed heart failure.

PURPOSE: To assess the effects of hospital care by a specialist or nonspecialist physician, and by volume of treated patients, on mortality among hospitalized patients with newly diagnosed heart failure. METHODS: Data describing heart failure patients in Alberta, Canada, from April 1, 1994, to March 31, 2000, were extracted from hospital abstracts and analyzed using hierarchical regression, with adjustment for patient demographic characteristics, comorbid conditions, physician volume, physician specialty, and hospital volume. RESULTS: There were 16,162 hospital discharges for heart failure. Nonspecialist physicians were predominantly in the two lowest-volume quartiles (93%) and specialists were predominantly in the two highest-volume quartiles (68%). Considering the effects of volume alone and after adjustment for comorbidity, for each 10 additional hospital patients treated by a physician, the odds ratio for in-hospital mortality was 0.97 (95% confidence interval [CI]: 0.95 to 0.98), and the odds ratio for 1-year mortality was 0.99 (95% CI: 0.98 to 0.999). In analyses that considered both volume and specialty, the odds of in-hospital mortality decreased by 4% for each 10 additional in-hospital patients treated by a physician (odds ratio [OR] = 0.96; 95% CI: 0.95 to 0.98). In these same analyses, the odds ratio for in-hospital mortality was 1.32 (95% CI: 1.13 to 1.53) for general practitioners with specialist consultation and 1.32 (95% CI: 1.08 to 1.61) for specialists compared with general practitioners without specialist consultations. At 1 year, mortality was not associated significantly with the volume of in-hospital patients treated, or with the specialty of the treating physician. CONCLUSION: Treatment by high-volume physicians during hospitalization for newly diagnosed heart failure was associated with a decrease in mortality, but these benefits did not persist at 1 year. The increased mortality noted in patients treated by specialists may be due to residual confounding or unmeasured comorbidity.

Adult↗
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

Variations in rates of appropriate and inappropriate carotid endarterectomy for stroke prevention in 4 Canadian provinces.

BACKGROUND: Carotid endarterectomy (CE), when performed on appropriate patients, reduces the incidence of stroke, yet there are marked variations in rates of this procedure. We sought to determine reasons for the variation in CE rates in 4 Canadian provinces. METHODS: We identified all CEs performed in 4 Canadian provinces between January 2000 and December 2001, inclusive. From chart review and expert assessment, we determined the proportion of these procedures that were appropriate, inappropriate or of uncertain appropriateness, using the RAND/UCLA Appropriateness Method. We sought to determine the variation in rates by province and whether the variation was due to differences in type of hospital, surgical specialty or surgical volume. RESULTS: Overall, 1656 (52.3%) of the 3167 CEs studied were performed for appropriate indications. The proportions of appropriate procedures were 78.2% (176/225) in Saskatchewan, 58.7% (481/819) in Alberta, 49.1% (350/713) in Manitoba and 46.0% (649/1410) in British Columbia (p < 0.001 across provinces). Rates of appropriate procedures per 100 000 population ranged from 44.3 in Manitoba to 16.2 in Saskatchewan (p < 0.001 across provinces). CEs were more likely to be appropriate when performed by a neurosurgeon compared with all other surgeons (74.4% v. 49.4% were appropriate; p < 0.001), when performed by surgeons doing fewer than 31 procedures over 2 years compared with surgeons doing more than 31 (70.1% v. 49.5% were appropriate; p < 0.001) and when performed in hospitals doing fewer than 135 procedures per year compared with hospitals doing more than 135 (63.4% v. 49.1% were appropriate; p < 0.001). Overall, 10.3% of procedures were done for inappropriate reasons. INTERPRETATION: Our findings suggest some overuse (for inappropriate or uncertain indications) but also some underuse (low population rates in some regions). High rates of CE are associated with lower rates of appropriateness for both surgeons and hospitals. That 1 in 10 CEs is done inappropriately suggests the need for preoperative assessment of appropriateness.

Adult↗
PubMed2004

An audit tool for assessing the appropriateness of carotid endarterectomy.

BACKGROUND: To update appropriateness ratings for carotid endarterectomy using the best clinical evidence and to develop a tool to audit the procedure's use. METHODS: A nine-member expert panel drawn from all the Canadian Specialist societies that are involved in the care of patients with carotid artery disease, used the RAND Appropriateness Methodology to rate scenarios where carotid endarterectomy may be performed. A 9-point rating scale was used that permits the categorization of the use of carotid endarterectomy as appropriate, uncertain, or inappropriate. A descriptive analysis was undertaken of the final results of the panel meeting. A database and code were then developed to rate all carotid endarterectomies performed in a Western Canadian Health region from 1997 to 2001. RESULTS: All scenarios for severe symptomatic stenosis (70-99%) were determined to be appropriate. The ratings for moderate symptomatic stenosis (50-69%) ranged from appropriate to inappropriate. It was never considered appropriate to perform endarterectomy for mild stenosis (0-49%) or for chronic occlusions. Endarterectomy for asymptomatic carotid disease was thought to be of uncertain benefit at best. The majority of indications for the combination of endarterectomy either prior to, or at time of coronary artery bypass grafting were inappropriate. The audit tool classified 98.0% of all cases. CONCLUSIONS: These expert panel ratings, based on the best evidence currently available, provide a comprehensive and updated guide to appropriate use of carotid endarterectomy. The resulting audit tool can be downloaded by readers from the Internet and immediately used for hospital audits of carotid endarterectomy appropriateness.

Algorithms↗
PubMed2004

Importance of the imaging modality in decision making about carotid endarterectomy.

OBJECTIVE: To determine the influence of all possible imaging strategies on the appropriateness ratings for carotid endarterectomy, because less accurate noninvasive techniques are replacing contrast angiography, which was used in the major efficacy trials. METHODS: An expert panel, using appropriateness methodology, rated 203 scenarios where endarterectomy might be performed. Each scenario was rated where internal carotid artery stenosis was determined using five different imaging sources: 1) conventional angiography, 2) ultrasound carotid Doppler only, 3) CT (CTA) or MR (MRA) angiography only, 4) concordant results from two noninvasive carotid imaging studies, and 5) discordant results from two noninvasive studies. The scenarios deemed appropriate by conventional angiography were identified. The effect of the other imaging modalities on these results was examined. RESULTS: Thirty-three scenarios were identified as being appropriate. Concordant imaging results had no effect on appropriateness ratings in symptomatic carotid artery disease when compared with conventional angiography. Single noninvasive imaging techniques were deemed appropriate for investigation only in the presence of severe symptomatic stenosis. In all other scenarios, single noninvasive imaging and discordant results reduced the appropriateness rating of scenarios to either uncertain benefit or inappropriateness. The single appropriate scenario for asymptomatic carotid artery stenosis was where severe stenosis was determined by concordant noninvasive imaging or by CTA or MRA alone. CONCLUSION: It is important to take into account both the clinical scenario and the imaging modalities utilized to determine the degree of internal carotid artery stenosis in the clinical decision making surrounding carotid endarterectomy.

Angiography↗
PubMed2004

The province of Alberta, Canada avoids the hospitalization epidemic for congestive heart failure patients.

BACKGROUND: We assessed the incidence and prevalence of congestive heart failure (CHF) in patients diagnosed at the time of hospitalization and patients diagnosed in specialists offices without prior hospitalization in order to compare the trends in Canada with previously published trends in the USA and other industrialized countries. METHODS: Administrative data for Alberta, Canada from 1 April 1994 to 31 March 2000. RESULTS: There was a small but statistically significant decline in the age-sex incident and prevalent hospitalization rates for CHF between 1994/1995 (incidence per 1000 of 1.59; 99% CI 1.51, 1.66: prevalence per 1000 of 2.31; 99% CI 2.22, 2.40) and the year 1999/2000 (incidence per 1000 of 1.24; 99% CI 1.18, 1.30: prevalence per 1000 of 1.97; 99% CI 1.89, 2.05). Crude hospitalization rate per 1000 also demonstrated a small but statistically significant decline between 1994/1995 (2.98; 99% CI 2.88, 3.08) and 1999/2000 (2.55; 99% CI 2.46, 2.64). The age-sex incident rates of ambulatory diagnosis of CHF were similar throughout the 1994/1995-1999/2000 time period (0.88; 99% CI 0.82, 0.94 during 1994/1995 and 0.84; 99% CI 0.79, 0.89 during 1999/2000). The crude mortality percentage for incident hospitalization for CHF were similar throughout the 1994/1995-1999/2000 time period (31.0%; 99% CI 28.7, 33.3 during 1994/1995 and 28.6%; 99% CI 26.3, 30.9 during 1999/2000). CONCLUSIONS: We noted a small decrease in the incident, prevalent, and total hospitalizations for CHF in the time period 1994/1995-1999/2000. The decrease was not the result of a substituted increase in ambulatory diagnosis for CHF.

Aged↗
PubMed2004

Assessing accuracy of diagnosis-type indicators for flagging complications in administrative data.

OBJECTIVE: Canadian administrative hospital discharge data contain a diagnosis-type indicator for each coded diagnosis that allows researchers to distinguish complications from pre-existing diagnoses. Given that the validity of diagnosis-type indicators is unknown, we conducted a detailed chart review to evaluate the accuracy of diagnosis-type indicators for flagging complications. STUDY DESIGN AND SETTING: We obtained administrative hospital discharge data for 1,200 randomly selected adult inpatient separations in Calgary, Alberta, occurring between April 1, 1996 and March 31, 1997. Each discharge record contains up to 16 diagnoses and 16 corresponding diagnosis-type indicators (value of "2"=complication). The corresponding medical charts were reviewed for evidence of diagnoses and complications. A complication was defined as a new diagnosis arising after the start of hospitalization. We determined the extent to which the diagnosis-type indicator in the administrative data agreed with the chart reviewer's assessment (criterion standard) of whether a diagnosis was a complication or not. RESULTS: The agreement for complications between the two databases varied greatly across 12 conditions studied (kappa range: 0-0.72) and was often low (kappa <0.20 for six conditions). Sensitivity ranged from 0 to 57.1% (higher than 50% for only two conditions), indicating a tendency for complications to often be miscoded as baseline comorbidities. In contrast, specificity was generally high (range: 99.0-100%), suggesting that pre-existing conditions were usually appropriately coded as such in the administrative data. CONCLUSION: The validity of diagnosis-type indicators in Canadian administrative discharge data appears to be poor for some types of complications. This is likely to be of greatest concern in studies that rely solely on diagnosis-type indicators to define complications as outcomes.

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↗