L. Duncan Saunders

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 Deyos (for Charlson comorbidities) and Elixhausers 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 Deyos 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.

The epidemiology of traumatic spinal cord injury in Alberta, Canada

OBJECTIVES To describe the incidence and pattern of traumatic spinal cord injury and cauda equina injury (SCI) in a geographically defined region of Canada. METHODS The study period was April 1, 1997 to March 31, 2000. Data were gathered from three provincial sources: administrative data from the Alberta Ministry of Health and Wellness, records from the Alberta Trauma Registry, and death certificates from the Office of the Medical Examiner. RESULTS From all three data sources, 450 cases of SCI were identified. Of these, 71 (15.8%) died prior to hospitalization. The annual incidence rate was 52.5/million population (95% CI: 47.7, 57.4). For those who survived to hospital admission, the incidence rate was 44.3/million/year (95% CI: 39.8, 48.7). The incidence rates for males were consistently higher than for females for all age groups. Motor vehicle collisions accounted for 56.4% of injuries, followed by falls (19.1%). The highest incidence of motor vehicle-related SCI occurred to those between 15 and 29 years (60/million/year). Fall-related injuries primarily occurred to those older than 60 years (45/million/year). Rural residents were 2.5 times as likely to be injured as urban residents. CONCLUSION Prevention strategies for SCI should target males of all ages, adolescents and young adults of both sexes, rural residents, motor vehicle collisions, and fall prevention for those older than 60 years.

Best practices for elderly hip fracture patients. A systematic overview of the evidence.

OBJECTIVES: To determine evidence-based best practices for elderly hip fracture patients from the time of hospital admission to 6 months postfracture. DATA SOURCES: MEDLINE, Cochrane Library, CINAHL, Embase, PEDro, Ageline, NARIC, and CIRRIE databases were searched for potentially eligible articles published between 1985 and 2004. REVIEW METHODS: Two independent reviewers determined studies appropriate for inclusion using standardized selection criteria, extracted data, evaluated internal validity, and then rated studies according to levels of evidence. Only Level 1 or 2 evidence was included in our summary of clinical recommendations. RESULTS: Spinal anesthesia, pressure-relieving mattresses, perioperative antibiotics, and deep vein thromboses prophylaxes had consistent evidence of benefit. Routine preoperative traction was not associated with any benefits and should be abandoned. Types of surgical management, postoperative wound drainage, and even “multidisciplinary” care, lacked sufficient evidence to determine either benefit or harm. There was little evidence to either determine best subacute rehabilitation practices or to direct ongoing medical issues (e.g., nutrition). Studies conducted during the subacute recovery period were heterogeneous in terms of treatment settings, interventions, and outcomes studied and had no clear evidence for best treatment practices. CONCLUSIONS: The evidence for perioperative practices is relatively robust and evidence-based perioperative treatment guidelines can be easily established. Conversely, more evidence is required to better guide the care of elderly patients with hip fracture during the subacute recovery period and convalescence.

Impact of pregnancy-induced hypertension on fetal growth

OBJECTIVE The purpose of this study was to evaluate the effect of different types of pregnancy-induced hypertension on fetal growth. STUDY DESIGN A retrospective cohort study was conducted on the basis of 16,936 births from January 1, 1989, through December 31, 1990, by means of data from a population-based perinatal database in Suzhou, China. Pregnancy-induced hypertension was classified as gestational hypertension, preeclampsia, or severe preeclampsia-eclampsia. Univariate and multivariate regression analyses were performed to examine the effect of the various types of pregnancy-induced hypertension on gestational age, preterm birth, birth weight, low birth weight, and intrauterine growth restriction. RESULTS Gestation was 0.6 week shorter in women with severe preeclampsia than in normotensive women (P <.01). However, the risk of preterm birth was not increased with any classification of pregnancy-induced hypertension (for severe preeclampsia: adjusted odds ratio 1.75; 95% confidence interval, 0.88-3.47). After adjustment for duration of gestation and other confounders, preeclampsia and severe preeclampsia increased the risk of intrauterine growth restriction and low birth weight. The adjusted odds ratios of low birth weight were 2.65 (1.73-4.39) for preeclampsia and 2.53 (1.19-4.93) for severe preeclampsia. However, the risk of low birth weight was not increased significantly for gestational hypertension (adjusted odds ratio 1.56 [1.00-2.41]). CONCLUSION Preeclampsia increases the risk of intrauterine growth restriction and low birth weight.

Sex Differences in Access to Coronary Revascularization after Cardiac Catheterization: Importance of Detailed Clinical Data

Context Women are less likely to be offered therapeutic cardiac procedures than men; however, the reasongender bias or clinical factorsis unknown. Contribution This study of coronary revascularization procedures during the year after catheterization compared men and women with the same extent of coronary artery disease and ejection fraction. The rate of coronary revascularization was the same in men and women. Implications The sex differences in cardiac procedure rates after catheterization appear to reflect appropriate decisions rather than gender bias. However, sex-based differences in catheterization rates remain unexplained. The Editors Reports of sex differences in the likelihood of undergoing cardiac procedures have led to suggestions of gender bias in cardiac care decision making (1-14). Other proposed explanations for the variation in use of cardiac procedures between sexes include differing patient preferences or differing clinical characteristics (for example, smaller coronary vessels in women). Earlier studies did not unanimously find sex differences in cardiac procedure rates; some studies reported equivalent procedure rates for men and women (15-21). The inconsistency across studies may be related to differences in geographic regions and health systems. However, another possible explanation is that many earlier studies evaluated highly selected patient samples that may not reflect processes of care at a population level. Yet another possible explanation is that the published studies on this issue have used various data sources, ranging from highly detailed data from clinical trials to sparsely detailed administrative data. The Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) is a population-based registry that captures detailed clinical information on all adult patients undergoing cardiac catheterization in the province of Alberta, Canada (22). The clinically detailed data generated by APPROACH provide a unique opportunity to study sex differences in access to revascularization after cardiac catheterization without the limitations of a nonrepresentative study sample or insufficiently detailed clinical data. Furthermore, the detailed APPROACH data allow us to assess whether comorbid conditions, extent of coronary disease, and ejection fraction account for or explain any observed sex differences in access to revascularization procedurespercutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery. Using a two-step process, we statistically adjusted crude (unadjusted) rates of cardiac revascularization for men and women in the year following cardiac catheterization. The first (partial) adjustment was based on baseline clinical variables that are routinely available in most databases, including administrative databases. The second (full) adjustment also controlled for extent of coro nary disease and ejection fraction, variables that are uniquely available for a large unselected patient population in APPROACH data. Methods Data Source and Variables The APPROACH database is an inception cohort database that captures clinical information on all patients undergoing cardiac catheterization in Alberta, Canada (22). This province has a population of approximately 2.8 million persons, of whom 10% identify themselves as ethnic minorities (3.5% are of Chinese ethnicity, 2% are of South Asian ethnicity, 1% are black, and 4.5% are aboriginal inhabitants). In 1996, median individual income levels for postal codedefined regions ranged from

Lymphovascular Invasion Is Associated With Poor Survival in Gastric Cancer: An Application of Gene-Expression and Tissue Array Techniques

12 000 to

Depression following Traumatic Spinal Cord Injury

37 000 Canadian per year. Sixty-seven percent of Albertans older than 20 years of age have a high school diploma, and 25% have some university-level education. Patients in APPROACH are followed longitudinally for assessment of long-term outcomes after cardiac catheterization. Clinical risk variables recorded at the time of cardiac catheterization are age, sex, diabetes mellitus, cerebrovascular disease, congestive heart failure, chronic pulmonary disease, elevated creatinine level ( 200 mmol/L [ 22.62 g/L]), dialysis status, hyperlipidemia, hypertension, liver or gastrointestinal disease, malignancy or metastatic disease, previous myocardial infarction, previous thrombolytic therapy for myocardial infarction, and peripheral vascular disease. The indication for catheterization is recorded in one of four categories: myocardial infarction within 8 weeks of catheterization, unstable angina, stable angina, or other (for example, arrhythmias without associated angina, or study protocols). The results of cardiac catheterization, including extent of coronary disease and left ventricular ejection fraction, are also recorded. We graded extent of coronary disease according to six categories: normal or near normal, one- to two-vessel disease, two-vessel disease with proximal left anterior descending artery involvement, three-vessel disease, three-vessel disease with proximal left anterior descending artery involvement, or left main disease. A diseased vessel was one that contained a lesion involving more than 50% of the vessel diameter. Left ventricular ejection fraction was graded according to five categories: greater than 50%, 30% to 50%, less than 30%, ventriculography not done (usually because of renal insufficiency or severely depressed cardiac function), and data missing. The APPROACH database accurately captures the occurrence of revascularization procedures in Alberta hospitals and the time to revascularization after cardiac catheterization. We analyzed data from patients undergoing cardiac catheterization from 1995 through 1998, with follow-up data through 1999. The Ethics Review Boards of the University of Calgary and the University of Alberta, Canada, approved the APPROACH study protocol. Statistical Analysis We performed a chi-square test and two-sample t-tests to compare the clinical characteristics of men and women undergoing catheterization. Chi-square tests and log-rank tests were used to compare the unadjusted proportions of men and women having revascularization procedures within 1 year after cardiac catheterization. We then used multivariable Cox proportional-hazards analyses to control revascularization rates for differences in clinical characteristics between men and women undergoing catheterization. For these analyses, we modeled time to 1) any revascularization procedure, 2) PCI, and 3) CABG surgery, with follow-up to 1 year. We initially calculated crude relative risks for procedures for women relative to men and then sequentially modeled two sets of variables. First, for the partially adjusted model, we used a set of clinical variables (age, indication for cardiac catheterization, cardiac history, and the comorbidity variables listed earlier) that would generally be available in most administrative databases (throughout the paper, we call this initial step partial adjustment). Second, for the fully adjusted model, we added two clinical variables, left ventricular ejection fraction and extent of coronary disease, that are uniquely available at a population level in the clinically detailed APPROACH database. The relative risk for women compared with men was the variable of interest for each of the models generated. We calculated and plotted risk-adjusted time-to-revascularization curves for men and women by applying the corrected group prognosis method to the proportional hazards models that generated fully adjusted relative risks (23). By plotting log[log S(t)] versus t and log(t) for all of the above models, we found that the proportional hazards assumption was appropriate for all variables included in the models, except the variable of indication for cardiac catheterization. Therefore, we handled cardiac catheterization as a stratification variable in our models. To assess model performance, we also plotted both martingale and deviance residuals for individual observations and found that none of the observations were widely deviant (that is, almost all deviance residuals were between 1.96 and 1.96). We examined influential observations by measuring the changes in the coefficients after dropping each observation from the data. For sex, the most influential observations changed the coefficient by less than 5% of the standard error. The software product used to perform data analyses was S-PLUS 5 for Linux, version 5.1 (Insightful Corp., Seattle, Washington). Role of the Funding Sources The funding sources had no role in the design, conduct, or reporting of this study. Results A total of 21 816 patients underwent cardiac catheterization in Alberta between 1 January 1995 and 31 December 1998. Of these patients, 15 409 (70.6%) were men and 6407 (29.4%) were women. Within 1 year after catheterization, 8488 of the 15 409 men (55.1%) had undergone a revascularization procedure (PCI or CABG surgery) compared with only 2574 of the 6407 women (40.2%) (P < 0.001). The proportion having undergone PCI at 1 year was 32.2% for men versus 26.1% for women (P < 0.001). The proportion having CABG surgery by 1 year after catheterization was 22.9% for men and only 14.0% for women (P < 0.001). In a proportional hazards analysis, the corresponding crude relative risk (that is, the likelihood) for having any revascularization procedure for women compared with men was 0.67 (95% CI, 0.65 to 0.71). For PCI and CABG surgery, the corresponding relative risks were 0.77 (CI, 0.73 to 0.82) and 0.54 (0.51 to 0.58), respectively. Thus, in relative terms, women were 33% less likely to undergo any revascularization procedure, 23% less likely to undergo PCI, and 46% less likely to undergo CABG surgery than were men. Clinical Characteristics Clinical characteristics of men and women differed (Table 1). Men tended to be younger and had fewer comorbid conditions, including a lower prevalence of chronic lung disease, cerebrovascular disease, hypertension, diabetes mellitus, liver disease, and congestive heart failure. However, men

Assessing the Methodological Quality of Nonrandomized Intervention Studies

Objectives:To examine a population-based cohort for the association between clinicopathologic predictors of survival and immunohistochemical markers (IHC), and to assess changes in gene expression that are associated with lymphovascular invasion (LVI). Summary Background Data:LVI has been associated with poor survival and aggressive tumor behavior. The molecular changes responsible for the behavior of gastric cancer have yet to be determined. Characterization of IHC markers and gene expression profiles may identify molecular alterations governing tumor behavior. Methods:Clinicopathologic and survival data of 114 patients were reviewed. Archival specimens were used to construct a multitumor tissue array that was subjected to IHC of selected protein targets. Correlation of IHC with tumor thickness (T status), LVI and prognosis was studied. Microarray analysis of fresh gastric cancer tissue was conducted to examine the gene expression profile with respect to LVI. Results:In a multivariate analysis, nodal status (N), metastasis (M), and LVI were independent predictors of survival. LVI was associated with a 5-year survival of 13.9% versus 55.9% in patients in whom it was absent. LVI correlated with advancing T status (P = 0.001) and N status (P < 0.001). IHC staining of cyclooxygenase-2 (COX-2) correlated with T status, tumor grade, lymph node positivity, and IHC staining of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Microarray analyses suggested differential expression of oligophrenin-1 (OPHN1) and ribophorin-II (RPNII) with respect to LVI. Conclusion:LVI was an independent predictor of survival in gastric cancer. Expression of COX-2 may facilitate tumor invasion through MMP-2 and MMP-9 activation. OPHN1 and RPN II appeared to be differentially expressed in gastric cancers exhibiting LVI. The reported function of OPHN1 and RPN II makes these gene products promising candidates for future studies involving LVI in gastric cancer.

Gender-related mortality for HIV-infected patients on highly active antiretroviral therapy (HAART) in rural Uganda

Objectives: To describe the epidemiology of depression following traumatic spinal cord injury (SCI) and identify risk factors associated with depression. Methods: This population-based cohort study followed individuals from date of SCI to 6 years after injury. Administrative data from a Canadian province with a universal publicly funded health care system and centralized databases were used. A Cox proportional hazards model was developed to identify risk factors. Results: Of 201 patients with SCI, 58 (28.9%) were treated for depression. Individuals at highest risk were those with a pre-injury history of depression [hazard rate ratio (HRR) 1.6; 95% CI: 1.1–2.3], a history of substance abuse (HRR 1.6; 95% CI: 1.2–2.3) or permanent neurological deficit (HRR 1.6; 95% CI: 1.2–2.1). Conclusion: Depression occurs commonly and early in persons who sustain an SCI. Both patient and injury factors are associated with the development of depression. These should be used to target patients for mental health assessment and services during initial hospitalization and following discharge into the community.

Antiretroviral treatment for HIV in rural Uganda: two-year treatment outcomes of a prospective health centre/community-based and hospital-based cohort.

In many areas of health care, randomized controlled trials (the best evidence regarding the effectiveness of health care interventions) are lacking and decision-makers have to rely on evidence from nonrandomized studies (NRS). We conducted a Medline search to identify English-language articles describing instruments for assessing the quality of NRS of health care interventions. These instruments varied greatly in scope, in the number and types of items and in developmental rigor. Items commonly included were those related to specification of study questions, allocation method, comparability of groups, and blinding of outcome assessment. We do not support the development of a generic scale to evaluate the methodological quality of nonrandomized intervention studies. Instead, further study should be directed to investigate the degree to which, and the circumstances under which, different methodological characteristics are associated with bias. This information will assist researchers in identifying a priori which methodological characteristics need careful evaluation in particular studies.