Do Diagnostic and Procedure Codes Within Population-Based, Administrative Datasets Accurately Identify Patients with Rectal Cancer?

BACKGROUND: Procedural and diagnostic codes may inaccurately identify specific patient populations within administrative datasets. PURPOSE: Measure the accuracy of previously used coding algorithms using administrative data to identify patients with rectal cancer resections (RCR). METHODS: Using a previously published coding algorithm, we re-created a RCR cohort within administrative databases, limiting the search to a single institution. The accuracy of this cohort was determined against a gold standard reference population. A systematic review of the literature was then performed to identify studies that use similar coding methods to identify RCR cohorts and whether or not they comment on accuracy. RESULTS: Over the course of the study period, there were 664,075 hospitalizations at our institution. Previously used coding algorithms identified 1131 RCRs (administrative data incidence 1.70 per 1000 hospitalizations). The gold standard reference population was 821 RCR over the same period (1.24 per 1000 hospitalizations). Administrative data methods yielded a RCR cohort of moderate accuracy (sensitivity 89.5%, specificity 99.9%) and poor positive predictive value (64.9%). Literature search identified 18 studies that utilized similar coding methods to derive a RCR cohort. Only 1/18 (5.6%) reported on the accuracy of their study cohort. CONCLUSIONS: The use of diagnostic and procedure codes to identify RCR within administrative datasets may be subject to misclassification bias because of low PPV. This underscores the importance of reporting on the accuracy of RCR cohorts derived within population-based datasets.

Impact of patient characteristics on the Canadian Patient Experiences Survey-Inpatient Care: survey analysis from an academic tertiary care centre.

OBJECTIVE: To determine the role of patient demographics, care domains and self-perceived health status in the analysis and interpretation of results from the Canadian Patient Experience Survey-Inpatient Care. DESIGN: Cross-sectional survey. SETTING: Single large Canadian two campus tertiary care academic centre. PARTICIPANTS: Random sampling of hospital patients postdischarge. INTERVENTION AND MAIN OUTCOME MEASURES: Logistic regression models were developed to analyse topbox scoring on four questions of global care (rate experience, recommend hospital, rate hospital, overall helped). Means of each composite domain were correlated to the four overall scores at the patient level to determine Spearman's rank correlation coefficients which were plotted against the overall (hospital) domain score for the key driver analysis. RESULTS: Topbox scoring was decreased with worse degrees of perceived physical and mental health in all four global questions (p<0.05). Female gender and higher levels of education were associated with worse scoring on rate experience, recommend hospital and rate hospital (p<0.001). Whereas there was a significant difference between hospital departments in unadjusted measures, these differences were no longer evident after adjustment with patient covariates. Key driver analysis identified person-centred care, care transition and the domain related to emergency admission as areas of highest potential for improvement. CONCLUSIONS: Global measures of overall care are influenced by patient-perceived physical and mental health. Caution should be exercised in using patient-satisfaction surveys to compare performance between different healthcare provision entities, as apparent differences could be explained by variation in patient mix rather than variation in performance.

Can Text-Search Methods of Pathology Reports Accurately Identify Patients with Rectal Cancer in Large Administrative Databases?

BACKGROUND: The aim of this study is to derive and to validate a cohort of rectal cancer surgical patients within administrative datasets using text-search analysis of pathology reports. MATERIALS AND METHODS: A text-search algorithm was developed and validated on pathology reports from 694 known rectal cancers, 1000 known colon cancers, and 1000 noncolorectal specimens. The algorithm was applied to all pathology reports available within the Ottawa Hospital Data Warehouse from 1996 to 2010. Identified pathology reports were validated as rectal cancer specimens through manual chart review. Sensitivity, specificity, and positive predictive value (PPV) of the text-search methodology were calculated. RESULTS: In the derivation cohort of pathology reports (n = 2694), the text-search algorithm had a sensitivity and specificity of 100% and 98.6%, respectively. When this algorithm was applied to all pathology reports from 1996 to 2010 (n = 284,032), 5588 pathology reports were identified as consistent with rectal cancer. Medical record review determined that 4550 patients did not have rectal cancer, leaving a final cohort of 1038 rectal cancer patients. Sensitivity and specificity of the text-search algorithm were 100% and 98.4%, respectively. PPV of the algorithm was 18.6%. CONCLUSIONS: Text-search methodology is a feasible way to identify all rectal cancer surgery patients through administrative datasets with high sensitivity and specificity. However, in the presence of a low pretest probability, text-search methods must be combined with a validation method, such as manual chart review, to be a viable approach.

Time is of the essence: an observational time-motion study of internal medicine residents while they are on duty.

BACKGROUND: The effects of changes to resident physician duty hours need to be measureable. This time-motion study was done to record internal medicine residents' workflow while on duty and to determine the feasibility of capturing detailed data using a mobile electronic tool. METHODS: Junior and senior residents were shadowed by a single observer during six-hour blocks of time, covering all seven days. Activities were recorded in real-time. Eighty-nine activities grouped into nine categories were determined a priori. RESULTS: A total of 17,714 events were recorded, encompassing 516 hours of observation. Time was apportioned in the following categories: Direct Patient Care (22%), Communication (19%), Personal tasks (15%), Documentation (14%), Education (13%), Indirect care (11%), Transit (6%), Administration (0.6%), and Non-physician tasks (0.4%). Nineteen percent of the education time was spent in self-directed learning activities. Only 9% of the total on duty time was spent in the presence of patients. Sixty-five percent of communication time was devoted to information transfer. A total of 968 interruptions were recorded which took on average 93.5 seconds each to service. CONCLUSION: Detailed recording of residents' workflow is feasible and can now lead to the measurement of the effects of future changes to residency training. Education activities accounted for 13% of on-duty time.

A Novel Neuroscience Intermediate-Level Care Unit Model: Retrospective Analysis of Impact on Patient Flow and Safety.

BACKGROUND AND PURPOSE: Neurointensive care units have been shown to improve patient outcomes across a variety of neurological and neurosurgical conditions. However, the efficacy of less resource-intensive intermediate-level care units to deliver similar care has not been well studied. The purpose of this study is to evaluate the impact of neurocritical specialist comanagement on patient flow and safety in a neuroscience intermediate-level care unit. METHODS: Our intervention consisted of the addition of a physician with critical care experience as well as training in neurology, anesthesiology, or intensive care to a neuroscience intermediate-level care unit to comanage patients alongside neurology and neurosurgery staff during weekday daytime hours. A retrospective analysis was performed on prospectively collected data pertaining to all patients admitted to the unit over a 3-year period, 1 year before our intervention and 2 years after. Patient statistics including wait times to admission, length of stay (LOS), and mortality were reviewed. RESULTS: Following the intervention, there were significant reductions in wait times to unit admission from both the emergency department and postanesthetic care unit, as well as reductions in the average LOS. No significant safety concerns were identified. CONCLUSION: This study has demonstrated that the optimization of a neuroscience intermediate-level care unit involving comanagement of patients by a neurocritical specialist can reduce wait times to admission and lengths of stay, with preserved safety outcomes.

Clinical characteristics and preventable acute care spending among a high cost inpatient population.

BACKGROUND: A small proportion of patients account for the majority of health care spending. The objectives of this study were to explore the clinical characteristics, patterns of health care use, and the proportion of acute care spending deemed potentially preventable among high cost inpatients within a Canadian acute-care hospital. METHODS: We identified all individuals within the Ottawa Hospital with one or more inpatient hospitalization between April 1, 2010 and March 31, 2011. Clinical characteristics and frequency of hospital encounters were captured in the information systems of the Ottawa Hospital Data Warehouse. Direct inpatient costs for each encounter were summed using case costing information and those in the upper first and fifth percentiles of the cumulative direct cost distribution were defined as extremely high cost and high cost respectively. We quantified preventable acute care spending as hospitalizations for ambulatory care sensitive conditions (ACSC) and spending attributable to difficulty discharging patients as measured by alternate level of care (ALC) status. RESULTS: During the study period, 36,892 patients had 44,066 hospitalizations. High cost patients (n = 1,844) accounted for 38 % of total inpatient spending ($122 million) and were older, more likely to be male, and had higher levels of co-morbidity compared to non-high cost patients. In over half of the high cost cohort (54 %), costs were accumulated from a single hospitalization. The majority of costs were related to nursing care and intensive care unit spending. High cost patients were more likely to have an encounter deemed to be ambulatory care sensitive compared to non-high cost inpatients (6.0 versus 2.8 %, p < 0.001). A greater proportion of inpatient spending was attributable to ALC days for high cost versus non-high cost patients (9.1 versus 4.9 %, p < 0.001). CONCLUSIONS: Within a population of high cost inpatients, the majority of costs are attributed to a single, non-preventable, acute care episode. However, there are likely opportunities to improve hospital efficiency by focusing on different approaches to community based care directed towards specific populations.

Variations in Resource Intensity and Cost Among High Users of the Emergency Department.

OBJECTIVES: High users of emergency department (ED) services are often identified by number of visits per year, with little exploration of the distribution/pattern of visits over time. The purpose of this study was to examine patient- and encounter-level factors and costs related to periods of short-term resource intensity among high users of the ED within a tertiary care teaching facility. METHODS: We identified all adults with at least three visits to the Ottawa Hospital ED within a 1-year period from April 1, 2012, to March 31, 2013. Within this high-user cohort, we then measured intensity of use by calculating average daily visit rates to identify individuals with a cluster of ED visits. Those with at least three ED visits/7 days at any point during follow-up were considered patients with clustered ED use (i.e., a period of short-term resource intensity). Detailed clinical and administrative data were used to compare patient- and encounter-level characteristics and cost profiles between the clustered and nonclustered groups. Analyses were repeated using varying cut points to define high users (at least five and at least eight visits per year). RESULTS: Of the 16,153 patients identified as high ED users during the study period, 13.5% had their visits clustered within a short period of time. These clustered users were more likely to be homeless, to require psychiatric services, and to leave without being seen by a physician and less likely to be admitted to the hospital. Approximately one in three (31.2%) high ED users with clustered visits returned for the same medical problem (namely pain-related disorders, shortness of breath, and cellulitis) within a 1-week period. Similar trends were observed when the high-user cohort was restricted to those with at least five and at least eight ED visits/year. Finally, patients with short-term intensity periods had lower direct and indirect costs per encounter than those without. CONCLUSIONS: Using a novel methodology that accounts for both number and intensity of ED encounters over time, we were able to identify specific subpopulations of high ED users. Further work is required to determine if this methodology has utility for targeting care pathways within this heterogeneous and high-risk patient group.

Time-motion studies of internal medicine residents' duty hours: a systematic review and meta-analysis.

BACKGROUND: Since the mid-1980s, medical residents' long duty hours have been under scrutiny as a factor affecting patient safety and the work environment for the residents. After several mandated changes in duty hours, it is important to understand how residents spend their time before proposing and implementing future changes. Time-motion methodology may provide reliable information on what residents do while on duty. PURPOSE: The purpose of this study is to review all available literature pertaining to time-motion studies of internal medicine residents while on a medicine service and to understand how much of their time is apportioned to various categories of tasks, and also to determine the effects of the Accreditation Council for Graduate Medical Education (ACGME)-mandated duty hour changes on resident workflow in North America. METHODS: Electronic bibliographic databases were searched for articles in English between 1941 and April 2013 reporting time-motion studies of internal medicine residents rotating through a general medicine service. RESULTS: Eight articles were included. Residents spent 41.8% of time in patient care activities, 18.1% communicating, 13.8% in educational activities, 19.7% in personal/other, and 6.6% in transit. North American data showed the following changes after the implementation of the ACGME 2003 duty hours standard: patient care activities from 41.8% to 40.8%, communication activities from 19.0% to 22.3%, educational activities from 17.7% to 11.6%, and personal/other activities from 21.5% to 17.1%. CONCLUSION: There was a paucity of time-motion data. There was great variability in the operational definitions of task categories reported in the studies. Implementation of the ACGME duty hour standards did not have a significant effect on the percentage of time spent in particular tasks. There are conflicting reports on how duty hour changes have affected patient safety. A low proportion of time spent in educational activities deserves further study and may point to a review of the educational models used.

Transfusion Patterns in All Patients Admitted to the Intensive Care Unit and in Those Who Die in Hospital: A Descriptive Analysis.

While it is known that the use of health care resources increases at the end of life in patients admitted to the Intensive Care Unit (ICU), the allocation of blood products at the end of life has not been described. The objective of this study was to describe overall transfusion patterns in the ICU, and specifically in patients who die in hospital. We conducted a retrospective cohort study of adult patients admitted to the ICU of a university-affiliated hospital, who were discharged or died between November 1, 2006 and June 30, 2012. During the study period, 10,642 patients were admitted at least once to the ICU. Of these patients, 4079 (38.3%) received red blood cells (RBCs), plasma or platelets in the ICU. The ICU mortality rate was 28.1% and in-hospital mortality rate was 32.3%. Among 39,591 blood product units transfused over the course of the study in the ICU (18,144 RBC units, 16,920 plasma units and 4527 platelet units), 46.2% were administered to patients who later died within the same hospitalization (41.2% of RBCs, 50.4% of plasma and 50.8% of platelets). Of all blood product units (RBCs, plasma and platelets) administered in the ICU over the study period, 11% were given within the last 24 hours before death. A large proportion of blood products used in the ICU are administered to patients who ultimately succumb to their illness in hospital, and many of these blood units are given in close proximity to death.

Changing trends in blood transfusion: an analysis of 244,013 hospitalizations.

BACKGROUND: Identifying recipients of blood transfusion and the trends in transfusion are needed to properly identify and target clinical services in need of patient blood management strategies. We determined the proportion of admissions to each clinical service that received blood, the mean number of units utilized, and the 5-year trends in utilization. STUDY DESIGN AND METHODS: We used a large administrative database, a repository for three campuses of one university-affiliated hospital, and included all adults that were hospitalized from November 1, 2006, to June 2012. The data were analyzed as the proportion of admissions transfused and the mean number units transfused per admission. RESULTS: Of 244,013 hospitalizations, 38,265 received at least one transfusion (29,165 for red blood cells [RBCs], 6760 for plasma, and 5795 for platelets [PLTs]). Although there has been a gradual decrease in the mean number of RBCs transfused (percent change, -9.8%; p = 0.002), an increase in the proportion of admissions receiving RBCs (17.2% increase, p < 0.0001) and PLTs (31.5% increase, p < 0.0001) was apparent while there has been a decrease in the proportion of admissions receiving plasma (23.9% decrease, p < 0.0001). Eight percent of cardiology admissions received RBCs, and the highest mean RBC utilization per admission, aside from the stem cell transplantation service, occurred in cardiology and critical care hospitalizations (mean, 4.7 units/hospitalization). CONCLUSION: Although there has been a reduction in the mean RBC units used, there has been an increase in the proportion of hospitalizations transfused. A better understanding of the indications for transfusion is required to facilitate the development of targeted blood conservation strategies.

Does anemia impact hospital readmissions after coronary artery bypass surgery?

BACKGROUND: Anemia is one of the most common complications of coronary artery bypass graft (CABG) surgery and has been shown to be associated with increased morbidity and mortality. The impact of anemia on hospital readmission after CABG, a potential measure of delayed complications, has not been addressed. STUDY DESIGN AND METHODS: We conducted a single-center retrospective study of 2102 patients who had CABG in Ontario to determine whether anemia at hospital discharge was associated with increased 30-day hospital readmissions, readmission secondary to cardiac disease, and 30-day mortality using administrative data. RESULTS: Of the 2102 patients, 224 patients (11%) were readmitted within 30 days of hospital discharge. Infection was the leading cause of readmissions (24%), followed by heart failure (13%), pulmonary disease (7%), and hemorrhagic disease (7%). Overall, 2.6% of patients were readmitted because of cardiac disease. Of patients discharged, 48% were discharged with a hemoglobin (Hb) level between 8 and 10 g/dL and 42% between 10 and 12 g/dL. Predischarge Hb concentration was not a significant independent predictor of 30-day readmission to the hospital due to all causes, readmission to the hospital due to cardiac causes, or 30-day mortality. A higher comorbidity score, adjusted odds ratio (OR) of 2.1 (95% confidence interval [CI], 1.3-3.6), leg and sternal wound infections OR of 1.9 (95% CI, 1.2-3.0), and postoperative renal failure OR of 1.4 (95% CI, 1.2-2.0) were associated with increased 30-day readmission rates. CONCLUSIONS: The predischarge Hb concentration after CABG was not associated with 30-day readmissions.

Patterns of emergency room visits, admissions and death following recommended pediatric vaccinations - a population based study of 969,519 vaccination events.

BACKGROUND: The risk of immediate adverse events due to the inflammation created by a vaccine is a potential concern for pediatric vaccine programs. METHODS: We analyzed data on children born between March 2006 and March 2009 in the province of Ontario. Using the self-controlled case series design, we examined the risk of the combined endpoint of emergency room visit and hospital admission in the immediate 3 days post vaccination to a control period 9-18 days after vaccination. We examined the end points of emergency room visits, hospital admissions and death separately as secondary outcomes. RESULTS: We examined 969,519 separate vaccination events. The relative incidence of our combined end point was 0.85 (0.80-0.90) for vaccination at age 2 months, 0.74 (0.69-0.79) at age 4 months and 0.68 (0.63-0.72) at age 6 months. The relative incidence was reduced for the individual endpoints of emergency room visits, admissions and death. There were 5 or fewer deaths in the risk interval of all 969,519 vaccination events. In a post hoc analysis we observed a large reduction in events in the immediate 3 days prior to vaccination suggesting a large healthy vaccinee effect. CONCLUSION: There was no increased incidence of the combined end point of emergency room visits and hospitalizations in the 3-day period immediately following vaccination, nor for individual endpoints or death. The health vaccinee effect could create the perception of worsening health following vaccines in the absence of any vaccine adverse effect and could also mask an effect in the immediate post-vaccination period.

Indications for and results of outpatient computed tomography and magnetic resonance imaging in Ontario.

OBJECTIVE: Population rates of computed tomography (CT) and magnetic resonance imaging (MRI) continue to increase markedly. However, little is known about the indications for and results of these imaging tests. METHODS: A cross-sectional chart-abstraction study was used to determine the indications for and results of outpatient CT and MRI scans performed on or after January 1, 2005, at randomly selected Ontario hospitals. RESULTS: We studied 11,824 CT and 11,867 MRI scans. Cancer-related indications accounted for over 50% of CT scans of the abdomen-pelvis and chest. Headache was the most frequent indication for CT of the brain. More than one-half of MRI scans of the extremities were for knee pain or suspected meniscal tear. Back pain and radiculopathy were the most frequent indications for MRI of the spine. There was considerable variation between institutions in ordering patterns, with as much as a 70-fold difference between hospitals in the frequency of scans ordered for a specific indication. Less than 2% of CT scans of the brain for headache found abnormalities that could explain the headache, while over 90% of MRI scans of the spine for back pain were abnormal, although the clinical importance of the abnormalities was unclear. CONCLUSIONS: These data are a starting point for a discussion about appropriateness. Further information will be obtained by examining individual indications more closely, and linking these data to administrative databases to evaluate the impact of these imaging tests on clinical practice.

Rates of new or missed colorectal cancers after colonoscopy and their risk factors: a population-based analysis.

BACKGROUND & AIMS: The rate of new or missed colorectal cancer (CRC) after colonoscopy and their risk factors in usual practice are unknown. Our objective was to evaluate the rate and risk factors in a population-based study. METHODS: We analyzed data from the Canadian Institute for Health Information, the Ontario Health Insurance Program, and Ontario Cancer Registry for all patients (> or =20 years of age) with a new diagnosis of right-sided, transverse, splenic flexure/descending, rectal or sigmoid CRC in Ontario from April 1, 1997 to March 31, 2002, who had a colonoscopy within the 3 years before their diagnosis. Patients with new or missed cancers were those whose most recent colonoscopy was 6 to 36 months before diagnosis. We examined characteristics that might be risk factors for new or missed CRC. RESULTS: We identified a diagnosis of CRC in 3288 (right sided), 777 (transverse), 710 (splenic flexure/descending), and 7712 (rectal or sigmoid) patients. The rates of new or missed cancers were 5.9%, 5.5%, 2.1%, and 2.3%, respectively. Independent risk factors for these cancers in men and women were older age; diverticular disease; right-sided or transverse CRC; colonoscopy by an internist or family physician; and colonoscopy in an office. CONCLUSIONS: Because having an office colonoscopy and certain patient, procedure, and physician characteristics are independent risk factors for new or missed CRC, physicians must inform patients of the small risk (2% to 6%) of these cancers after colonoscopy. The influence of type of physician and setting on the accuracy of colonoscopy, potentially modifiable risk factors, warrants further study.

Colorectal cancer screening with nurse-performed flexible sigmoidoscopy: results from a Canadian community-based program.

BACKGROUND: Despite highest-quality evidence that early detection of colorectal cancer (CRC) can lead to reduced mortality, no organized CRC screening programs exist in Canada. OBJECTIVE: To report the safety, the feasibility, and the detection rate for the first Canadian community-based nurse-performed flexible sigmoidoscopy (FS) screening program for CRC, established in 1999. DESIGN: Cross-sectional analysis of data collected from a prospective study of FS done by nurses from March 1999 to November 2002. Estimate of differences between men and women in FS findings, with relative risks. Logistic regression used to calculate odds ratios for advanced neoplasia. SETTING: Endoscopy suite of a community hospital. PATIENTS: Asymptomatic men and women > or =50 years, with no previous history of CRC. INTERVENTION: FS done by a nurses, and colonoscopy for persons with abnormalities done by an experienced gastroenterologist. MAIN OUTCOME MEASUREMENTS: Mean depth of insertion of endoscope; duration of FS procedure; number and location of polyps found during FS; number, location, and type of polyps found during colonoscopy. RESULTS: A total of 1818 individuals (mean age, 62 years) underwent nurse-performed FS (mean duration, 7.3 minutes; mean depth of insertion of the endoscope, 53.5 cm), without complications. Results of the FS were abnormal for 240 (13.2%) of the 1818 participants; 231 (12.7%) underwent colonoscopy. Distal neoplasms (adenomas or cancer) were detected in 8.7% (158/1818). After adjustment for age and family history of CRC, the risk of advanced neoplasm in the distal colon for men was about twice that for women (odds ratio 1.95, 95% confidence interval 1.21-3.14). Cancer was detected in 5 of the 1818 participants screened (0.28%), and high-grade dysplasia was detected in an additional 5 (0.28%). One of the cancers and all the lesions with high-grade dysplasia were treated endoscopically. CONCLUSIONS: Our community-based nurse-performed FS screening program was feasible and safe. The referral rate for colonoscopy was 13%, and the cancer detection rate was 2.8 per 1000 persons screened.

A rural CT scanner: evaluating the effect on local health care.

OBJECTIVE: The first small rural hospital in Ontario to propose a computed tomography (CT) scanner was in Walkerton, a town 160 km north of London. The Ontario Ministry of Health approved the proposal as a pilot project to evaluate the effect on local health care of a rural scanner. This evaluation study had 3 parts: a survey of physicians, a survey of patients, and an analysis of population CT scanning rates. METHOD: The physicians in the area served by the scanner were asked about its impact on their care of their patients in a mailed questionnaire and in semistructured interviews. Scanner outpatients were given a questionnaire in which they rated the importance of its advantages. The analysis of scanning rates--the ratio of number of scans to estimated population--compared rates in the area with other Ontario rates before and after the scanner was introduced. RESULTS: The physicians reported that local CT allowed them to diagnose and treat patients sooner, closer to home, and with greater confidence. On average, 75% of the patients ranked faster and closer access as very important. Scanning rates in the area rose, although they did not match urban rates. CONCLUSIONS: The study confirms that the rural scanner changed the area's health care in significant ways and that it helped to narrow the gap between rural and urban service levels. We recommend that CT be expanded to other rural regions.

Hospital volume and mortality for mechanical ventilation of medical and surgical patients: a population-based analysis using administrative data.

OBJECTIVE: In an effort to improve efficiency and quality of care, regionalization of adult critical care services, similar to trauma and neonatal intensive care, has been suggested. However, there is little research to understand if hospitals with higher patient volumes have better outcomes. Our objective is to determine whether hospital volume is associated with improved survival for medical or surgical patients receiving mechanical ventilation. DESIGN: Population-based retrospective cohort study. SETTING: Province of Ontario, Canada. PATIENTS: A total of 13,846 medical and 6,373 surgical patients receiving mechanical ventilation for greater than two consecutive days between 1998 and 2000. INTERVENTIONS: None. MEASUREMENTS: Odds ratio for death within 30 days of initiation of mechanical ventilation was calculated in relation to hospital volume of ventilation. Estimates were adjusted for patient demographics, diagnoses, and urgency status; hospital region and rural location; and accounted for clustering within hospitals. MAIN RESULTS: There was no effect of volume on mortality for surgical patients. After adjustment for clustering, among medical patients, the lowest-volume category (<100 episodes/yr) had a nonsignificant increase in mortality, with an odds ratio (95% confidence interval) of 1.13 (0.87-1.47) compared with the highest-volume category (> or =700 episodes/yr). A post hoc analysis revealed that within the lowest-volume category, the proportion of patients transferred to larger hospitals was 81% for hospitals with <20 episodes/yr and only 32% for hospitals with 20-99 episodes/yr, with odds ratios (95% confidence interval) for mortality of 0.74 (0.49-1.12) and 1.18 (0.90-1.54), respectively, compared with the highest-volume category. CONCLUSIONS: For surgical patients requiring mechanical ventilation for >2 days, hospital volume had no effect on mortality. For medical patients, higher mortality may occur in a subgroup of low-volume hospitals that do not routinely transfer their patients to larger-volume facilities. This finding needs further investigation in a larger-sized study.

Temporal trends in new diagnoses of colorectal cancer with obstruction, perforation, or emergency admission in Ontario: 1993-2001.

OBJECTIVES: Previous studies have shown that patients newly diagnosed with colorectal cancer requiring emergency admission to hospital or presenting with obstruction or perforation (defined here as OPE) have advanced disease. None of these studies, however, has evaluated temporal trends in these adverse outcomes, which may reflect screening failures. We evaluated temporal trends in the proportion of Ontario patients with a new diagnosis of colorectal cancer and OPE. METHODS: Data were obtained from four sources: the Ontario Cancer Registry (OCR); the Canadian Institute for Health Information (CIHI) database, which contains diagnostic information on all patients discharged from hospitals; the Ontario Health Insurance Plan (OHIP) database, which records all physician claims in Ontario; and the Registered Persons Database, which contains demographic information on all Ontario residents covered under OHIP. We calculated the proportion of patients (>/=20 yr) with a new diagnosis of colorectal cancer recorded in CIHI who presented with OPE between 1993 and 2001. These patients were assigned to one of three cohort years: 1993-1995, 1996-1998, or 1999-2001. Those who received chemotherapy, radiotherapy, or palliative care before their first admission to hospital were excluded. We repeated the analysis using the number of OPE patients identified from CIHI in the numerator, and the number of patients (>/=20 yr) with a new diagnosis of colorectal cancer recorded in the OCR in the denominator. Adjusted risk of OPE was calculated using a logistic regression model. RESULTS: Between 1993 and 2001, 59,670 patients with a new diagnosis of colorectal cancer were recorded in the CIHI database and 54,103 in the OCR. The proportion of these patients with OPE recorded in the CIHI decreased significantly over time: 23.8% (95% CI = 23.2-24.4%) during 1993-1995, 19.4% (95% CI = 18.8-20.0%) during 1996-1998, and 18.1% (95% CI 17.6-18.6%) during 1999-2001 (a 24% relative decrease over time). The relative decrease calculated from OCR data was similar. The adjusted relative decrease in the proportion of patients with OPE during 1993-2001 was 31%. CONCLUSIONS: Much greater emphasis on screening is needed since approximately 20% of patients with a new diagnosis of colorectal cancer in 1999-2001 presented with OPE.

The growing volume of diabetes-related dialysis: a population based study.

BACKGROUND: End-stage renal failure requiring dialysis is one of the most serious complications of diabetes mellitus, and diabetes is the most common cause of end-stage renal failure. The aim of this large, observational study is to describe the population-based incidence and prevalence rates and outcomes of diabetic individuals in Ontario, Canada who require dialysis therapy. METHODS: Two cohorts of patients, those with diabetes and those without, were created between April 1, 1994 and March 31, 2000 (total of approximately 8.4 million) and followed until March 31, 2001 using several large, linked administrative databases at the Institute for Clinical Evaluative Sciences. The incidence, prevalence and mortality on dialysis for each cohort were determined. A multivariate Cox proportional hazards analysis, adjusting for age, sex and co-morbidity, was used to determine the independent impact of diabetes on patient survival. RESULTS: The average annual incidence rate of dialysis was 12 times greater in persons with diabetes (130 per 100,000) vs without diabetes (11 per 100,000). By 1999-2000, diabetic patients comprised 51% of the incident dialysis population. The average annual prevalence rate was 10 times greater in the diabetic cohort. Patients with diabetes had more co-morbidities at the start of dialysis and poorer 3 year survival (55 vs 68%; P < 0.0001). CONCLUSIONS: The incident and prevalent rates of dialysis for patients with diabetes mellitus are many times the rates of those without diabetes. Patients with diabetes mellitus often start dialysis with significant co-morbidities, which may contribute to the relatively high rate of mortality on dialysis.

Antihypertensive therapy and incidence of type 2 diabetes in an elderly cohort.

OBJECTIVE: The aim of this study was to determine whether the incidence of type 2 diabetes differed among elderly users of four major antihypertensive drug classes. RESEARCH DESIGN AND METHODS: This was a retrospective, observational cohort study of previously untreated elderly patients (aged > or = 66 years) identified as new users of an antihypertensive drug class between April 1995 and March 2000. Using a Cox proportional hazards model, the primary analysis compared diabetes incidence in users of ACE inhibitors, beta-blockers, and calcium channel blockers (CCBs), with thiazide diuretics allowed as second-line therapy. In the secondary analysis, thiazide diuretics were added as a fourth study group. RESULTS: In the multivariable-adjusted primary analysis (n = 76,176), neither ACE inhibitor use (hazard ratio 0.96 [95% CI 0.84-1.1]) nor beta-blocker use (0.86 [0.74-1.0]) was associated with a statistically significant difference in type 2 diabetes incidence compared with the CCB control group. In the secondary analysis (n = 100,653), compared with CCB users, type 2 diabetes incidence was not significantly different between users of ACE inhibitors (0.97 [0.83-1.1]), beta-blockers (0.84 [0.7-1.0]), or thiazide diuretics (1.0 [0.89-1.2]). CONCLUSIONS: Type 2 diabetes incidence did not significantly differ among users of the major antihypertensive drug classes in this elderly, population-based administrative cohort. These results do not support the theory that different antihypertensive drug classes are relatively more or less likely to cause diabetes.