Let's get physical: A prospective pedometer study of doctors working in a South African emergency department.

BACKGROUND: The positive impact of physical activity and exercise on health is well known. Individuals who walk at least 10 000 steps per day are likely to meet recommended physical activity guidelines. Very little is known about the physical activity levels of doctors at work, in particular those working in emergency departments (EDs). OBJECTIVES: To determine how many steps per shift were taken by doctors in a South African (SA) ED. Secondary objectives were to assess what factors influenced the number of steps taken. METHODS: This was a prospective observational cohort study in a tertiary academic teaching hospital ED in Johannesburg over a 1-month period. Doctors wore pedometers during their day shifts in the ED and the number of steps taken during their shifts was measured, as well as the number and triage category of patients seen and whether cardiopulmonary resuscitation (CPR) was performed. RESULTS: The median (interquartile range) number of steps taken per shift was 6 328 (4 646 - 8 409). The number of steps taken exceeded the 10 000-step target in only 11.7% of shifts. The overall mean (standard deviation (SD)) number of steps per hour was 744 (490). Factors that significantly increased the number of steps taken included shift duration, number of patients seen who were triaged yellow, and performance of CPR in a shift. Each additional hour of shift led to a mean (SD) increase of 575 (115) steps. Each additional yellow patient seen led to a mean (SD) increase of 118 (108) steps. The mean (SD) number of steps for a shift with CPR was significantly higher (8 309 (850) steps) than for a shift without CPR (6 496 (384) steps). CONCLUSIONS: Doctors working in an SA ED are not achieving the daily recommended number of steps while at work. The increased risk of ill health and burnout in an already high-risk specialty heightens the importance of exercise and physical activity that needs to be achieved outside the workplace.

A literature-based cost analysis of tissue plasminogen activator for prevention of biliary stricture in donation after circulatory death liver transplantation.

INTRODUCTION: This study sought to approximate the cost-effectiveness of tPA utilization for prevention of biliary strictures (PTBS) in donation after circulatory death liver transplantation (DCD-LT). METHODS: Previously-reported PTBS rates in DCD-LT with and without tPA were used to calculate the number needed to treat (NNT) for prevention of one PTBS. The incremental cost of PTBS was then used to determine the cost effectiveness of tPA for prevention of PTBS. RESULTS: The incidence of PTBS in the setting of tPA administration was 20%, while incidence in patients without tPA use was 43% (p < 0.001). Meta-analysis demonstrated a risk reduction of 15.7%, which translated into a NNT of 6.4. Cost associated with treating 6.4 patients was $50,353. Based on an incremental cost of $81,888 associated with PTBS management, use of tPA in DCD-LT protocols was estimated to save $31,528 per PTBS prevented. CONCLUSION: Utilization of tPA in DCD-LT protocols represents one possible cost-effective strategy for prevention of PTBS in DCD-LT.

Implementation fidelity of a self-management course for epilepsy: method and assessment.

BACKGROUND: Complex interventions such as self-management courses are difficult to evaluate due to the many interacting components. The way complex interventions are delivered can influence the effect they have for patients, and can impact the interpretation of outcomes of clinical trials. Implementation fidelity evaluates whether complex interventions are delivered according to protocol. Such assessments have been used for one-to-one psychological interventions; however, the science is still developing for group interventions. METHODS: We developed and tested an instrument to measure implementation fidelity of a two-day self-management course for people with epilepsy, SMILE(UK). Using audio recordings, we looked at adherence and competence of course facilitators. Adherence was assessed by checklists. Competence was measured by scoring group interaction, an overall impression score and facilitator "didacticism". To measure "didacticism", we developed a novel way to calculate facilitator speech using computer software. Using this new instrument, implementation fidelity of SMILE(UK) was assessed on three modules of the course, for 28% of all courses delivered. RESULTS: Using the instrument for adherence, scores from two independent raters showed substantial agreement with weighted Kappa of 0.67 and high percent agreement of 81.2%. For didacticism, the results from both raters were highly correlated with an intraclass coefficient of 0.97 (p < 0.0001). We found that the courses were delivered with a good level of adherence (> 50% of scored items received the maximum of 2 points) and high competence. Groups were interactive (mean score: 1.9-2.0 out of 2) and the overall impression was on average assessed as "good". Didacticism varied from 42% to 93% of total module time and was not associated with the other competence scores. CONCLUSION: The instrument devised to measure implementation fidelity was reproducible and easy to use. The courses for the SMILE(UK) study were delivered with a good level of adherence to protocol while not compromising facilitator competence. TRIAL REGISTRATION: ISRCTN57937389 .

Real-time assessment of relapse risk based on the WT1 marker in acute leukemia and myelodysplastic syndrome patients after hematopoietic cell transplantation.

Relapse is the major cause of treatment failure after allogeneic hematopoietic cell transplantation (alloHCT) for acute leukemia and myelodysplastic syndrome (MDS). Wilms' tumor Ag (WT1) is overexpressed in the majority of acute leukemia and MDS patients and has been proposed as a universal diagnostic marker for detection of impending relapse. Comprehensive studies have shown that WT1 transcript levels have predictive value in acute leukemia patients in CR after chemotherapy. However, the focus of this study is the period after alloHCT for predicting relapse onset. We analyzed the accumulation of WT1 mRNA transcripts in PB of 82 leukemia and MDS patients and defined specific molecular ratios for relapse prediction. The extensively validated WT1/c-ABL ratio was used to normalize increases in WT1 transcript levels. The observed lead time of crossing or exceeding set WT1 levels is presented along with linear interpolation to estimate the calculated day the WT1 thresholds were crossed. The WT1/c-ABL transcript ratio of 50 or above yielded 100% specificity and 75% sensitivity reliably predicting future relapse with an observed average of 29.4 days (s.d.=19.8) and a calculated average of 63 days (s.d.=29.3) lead time before morphologic confirmation. A lower ratio of 20 or above gave lower specificity, but higher sensitivity (84.8% and 87.5%, respectively) identified more patients who relapsed, at earlier times, providing an earlier warning with actual average lead time of 49.1 days (s.d.=30.8) and calculated average of 78 days (s.d.=28.8). WT1 transcript levels serve as a diagnostic relapse test with greater sensitivity than the morphologic approach used in the clinic as a readout.

Use of electrical devices reveals our well being.

We want to objectivize the level of activity of elderly persons living independently at home. Most existing monitoring systems are intrusive and/or require a large number of sensors. We hope the "ubiquitous computing" concept could find an application in this context. We proposed to monitor the use of electrical appliances. We built a unique "activity indicator" which integrates all the activities of the person. This was assessed during 6 months within 12 flats occupied by single elderly persons.

Predictors of psychological distress in carers of people with amyotrophic lateral sclerosis: a longitudinal study.

BACKGROUND: The majority of people providing informal care for people with amyotrophic lateral sclerosis (ALS) are spouses. This prospective study set out to examine changes in and predictors of psychological distress in spouse carers of people with ALS. METHOD: Fifty spouse carers of people with ALS underwent an initial interview and at least 21 underwent two further interviews, at median intervals of approximately 5-6 months. They rated the functional impact of their partner's ALS on everyday activities and everyday cognitive, emotional and behavioural changes that might have occurred in the person with ALS. They also rated their own social support and marital relationship, and completed measures of mood, burden and strain. The ALS Severity Scale was also completed for their partner with ALS. RESULTS: Over time, carers' psychological distress (a global measure combining mood, burden and strain) increased significantly. Initially carers' psychological distress was best predicted by the psychosocial impact of their spouse/partners' ALS, the extent to which their partner demonstrated emotional lability and how many other people were considered as dependents of the carer. Subsequently, carer distress was best predicted by an initial measure of negative social support and by their initial satisfaction with their social relationships. CONCLUSIONS: Despite the significant physical impairment associated with ALS, psychosocial factors appear important in determining short- and longer-term psychological well-being in carers of people with ALS and may help clinicians to predict which carers are likely to experience psychological difficulties as part of their caring role.

Economic analysis of conventional-dose chemotherapy compared with high-dose chemotherapy plus autologous hematopoietic stem-cell transplantation for metastatic breast cancer.

We performed an economic analysis of data from 180 women in a clinical trial of conventional-dose chemotherapy vs high-dose chemotherapy plus stem-cell transplantation for metastatic breast cancer responding to first-line chemotherapy. Data on resource use, including hospitalizations, medical procedures, medications, and diagnostic tests, were abstracted from subjects' clinical trial records. Resources were valued using the Medicare Fee Schedule for inpatient costs at one academic medical center and average wholesale prices for medications. Monthly costs were calculated and stratified by treatment group and clinical phase. Mean follow-up was 690 days in the transplantation group and 758 days in the conventional-dose chemotherapy group. Subjects in the transplantation group were hospitalized for more days (28.6 vs 17.8, P=0.0041) and incurred higher costs (US dollars 84055 vs US dollars 28169) than subjects receiving conventional-dose chemotherapy, with a mean difference of US dollars 55886 (95% CI, US dollars 47298-US dollars 63666). Sensitivity analyses resulted in cost differences between the treatment groups from US dollars 36528 to US dollars 75531. High-dose chemotherapy plus stem-cell transplantation resulted in substantial additional morbidity and costs at no improvement in survival. Neither the survival results nor the economic findings support the use of this procedure outside of the clinical trial setting.

Retrospective assessment of initial stroke severity: comparison of the NIH Stroke Scale and the Canadian Neurological Scale.

BACKGROUND AND PURPOSE: The NIH Stroke Scale (NIHSS) and the Canadian Neurological Scale (CNS) have been reported to be useful for the retrospective assessment of initial stroke severity. However, unlike the CNS, the NIHSS requires detailed neurological assessments that may not be reflected in all patient records, potentially limiting its applicability. We assessed the reliability of the retrospective algorithms and the proportions of missing items for the NIHSS and CNS in stroke patients admitted to an academic medical center (AMC) and 2 community hospitals. METHODS: Randomly selected records of patients with ischemic stroke admitted to an AMC (n=20) and community hospitals with (CH1, n=19) and without (CH2, n=20) acute neurological consultative services were reviewed. NIHSS and CNS scores were assigned independently by 2 neurologists using published algorithms. Interrater reliability of the scores was determined with the intraclass correlation coefficient, and the numbers of missing items were tabulated. RESULTS: The intraclass correlation coefficient for NIHSS and CNS, respectively, were 0.93 (95% CI, 0.82 to 1.00) and 0.97 (95% CI, 0.90 to 1.00) for the AMC, 0.89 (95% CI, 0.75 to 1.00) and 0.88 (95%, 0.73 to 1.00) for the CH1, and 0.48 (95% CI, 0.26 to 0.70) and 0.78 (95% CI, 0.60 to 0.96) for the CH2. More NIHSS items were missing at the CH2 (62%) versus the AMC (27%) and the CH1 (23%, P:=0.0001). In comparison, 33%, 0%, and 8% of CNS items were missing from records from CH2, AMC, and CH1, respectively (P:=0.0001). CONCLUSIONS: The levels of interrater agreement were almost perfect for retrospectively assigned NIHSS and CNS scores for patients initially evaluated by a neurologist at both an AMC and a CH. Levels of agreement for the CNS were substantial at a CH2, but interrater agreement for the NIHSS was only moderate in this setting. The proportions of missing items are higher for the NIHSS than the CNS in each setting, particularly limiting its application in the hospital without acute neurological consultative services.

Assessment of aspiration risk in stroke patients with quantification of voluntary cough.

BACKGROUND: Dysphagia and subsequent aspiration are serious complications of acute stroke that may be related to an impaired cough reflex. It was hypothesized that aspirating stroke patients would have impaired objective measures of voluntary cough as compared with both nonstroke control subjects and nonaspirating stroke patients. METHODS: Swallowing was evaluated by standard radiologic or endoscopic methods, and stroke patients were grouped by aspiration severity (severe, n = 11; mild, n = 17; no aspiration, n = 15). Airflow patterns and sound pressure level (SPL) of voluntary cough were measured in stroke patients and in a group of normal control subjects (n = 18). Initial stroke severity was determined retrospectively with the Canadian Neurological Scale. RESULTS: All cough measures were altered in stroke patients as a group relative to nonstroke control subjects. Univariate analysis showed that peak flow of the inspiration phase (770.6 +/- 80.6 versus 1,120.1 +/- 148.4 mL/s), SPL (90.0 +/- 3.1 versus 100.2 +/- 1.6 dB), peak flow of the expulsive phase (875.1 +/- 122.7 versus 1,884.1 +/- 221.6 mL/s), expulsive phase rise time (0.34 +/- 0.1 versus 0.09 +/- 0.01 s), and cough volume acceleration (5.5 +/- 1.3 versus 27.8 +/- 3.9 mL/s/s) were significantly impaired in severe aspirators as compared with nonaspirators. Aspirating patients had more severe strokes than nonaspirators (mean Canadian Neurological Scale score 7.7 +/- 0.7 versus 9.8 +/- 0.3). Multivariate logistic regression found only expulsive phase rise time values during cough correlated with aspiration status. CONCLUSION: Objective analysis of cough may provide a noninvasive way to identify the aspiration risk of stroke patients.

Cost implications of specialized coagulation testing for acute ischemic stroke.

BACKGROUND AND PURPOSE: Hypercoagulable states are a rare but recognized cause of ischemic stroke. Evaluation for these coagulation disorders is costly, but establishing a diagnosis may lead to a change in treatment. We estimated the incremental cost of specialized coagulation testing per additional ischemic stroke patient placed on a regimen of warfarin therapy. METHODS: The cost-effectiveness analysis was performed based on data from a consecutive series of 674 adult ischemic stroke patients admitted to an academic medical center over a 3-year period. Those with atrial fibrillation or warfarin contraindications were excluded. Specialized coagulation test costs (protein C, protein S, antithrombin III, plasminogen, activated protein C resistance/factor V Leiden mutation, lupus anticoagulant, and anticardiolipin antibodies) were based on Medicare reimbursement rates. Effectiveness was defined as the difference in proportions of patients tested for coagulation disorders (coagulopathy present, normal complete battery, or incomplete) and treated with warfarin versus those patients who were not tested and treated with warfarin (the comparator). The incremental cost-effectiveness ratio (ICER) was defined as the cost associated with changing 1 patient to warfarin therapy. RESULTS: The base case ICER was $1,102 per additional patient treated with warfarin. The only factor that led to a significant change in the ICER was the proportion of untested patients treated with warfarin. The results of 2-way sensitivity analyses revealed a minimum ICER of $496 and a maximum ICER of $2,959. CONCLUSIONS: Strategies optimizing the selection of patients for specialized coagulation testing are needed. Outcomes-based cost-effectiveness cannot be determined until the impact of secondary prevention with anticoagulation in patients with specific coagulopathies is known.

A cost-effectiveness analysis of biliary anastomosis with or without T-tube after orthotopic liver transplantation.

Biliary reconstruction continues to be a major source of morbidity following orthotopic liver transplantation. We wished to determine if choledochocholedochostomy without a T-tube was associated with fewer biliary complications and was less costly than choledochocholedochostomy with a T-tube. A retrospective cohort study of patients who underwent liver transplantation was performed. Patients were stratified into two groups: group I had bile duct reconstruction with T-tube and group II did not have a T-tube. The results were interpreted on an intention-to-treat analysis. We identified 147 adult patients who underwent initial liver transplantation. There were 76 patients in group I and 71 patients in group II. There were no statistical differences between the two groups regarding underlying cause of liver disease, patient age, gender or United Network for Organ Sharing status. As the decision to use a T-tube was made at the time of surgery, the two groups may not be strictly comparable. The mean hospital stay was longer in group I (31.1 +/- 27.9d) than in group II (18.8 +/- 15.5d) (p = 0.001). Biliary complications were statistically more frequent in patients from group I patients (25/76, 32.9%) than in patients from group II (11/71, 15.5%) (p = 0.01). There was a trend for the costs associated with diagnostic and therapeutic procedures for the management of biliary complications to be greater for group I than for group II, although this was not statistically significant (p = 0.235). Our study suggests choledochocholedochostomy without T-tube reconstruction is the preferred strategy for biliary reconstruction in orthotopic liver transplantation. It is not only associated with fewer biliary complications, but also less costly than using choledochocholedochostomy over a T-tube. Randomized prospective studies are needed to confirm our results.

An efficacy and cost-effectiveness analysis of combination hepatitis B immune globulin and lamivudine to prevent recurrent hepatitis B after orthotopic liver transplantation compared with hepatitis B immune globulin monotherapy.

Orthotopic liver transplantation (OLT) for hepatitis B virus (HBV) infection was limited until recently by poor graft and patient outcomes caused by recurrent HBV. Long-term immunoprophylaxis with hepatitis B immune globulin (HBIG) dramatically improved post-OLT survival, but recurrent HBV still occurred in up to 36% of the recipients. More recently, combination HBIG and lamivudine has been shown to effectively prevent HBV recurrence in patients post-OLT. The aim of the current study is to determine long-term outcome and cost-effectiveness of using combination HBIG and lamivudine compared with HBIG monotherapy in patients who undergo OLT for HBV. A retrospective chart review identified 59 patients administered combination HBIG and lamivudine and 12 patients administered HBIG monotherapy as primary prophylaxis against recurrent HBV. Lamivudine, 150 mg/d, was administered orally indefinitely. HBIG was administered under a standard protocol (10,000 IU intravenously during the anhepatic phase, then 10,000 IU/d intravenously for 7 days, then 10,000 IU intravenously monthly) indefinitely. A decision-analysis model was developed to evaluate the potential economic impact of prophylaxis against HBV with combination therapy compared with monotherapy. Recurrent HBV was defined as the reappearance of hepatitis B surface antigen (HBsAg) after its initial disappearance post-OLT. In the combination-therapy group, no patient redeveloped serum HBsAg or HBV DNA during mean follow-ups of 459 and 416 days, respectively. In the monotherapy group, 3 patients (25%) had reappearance of HBsAg in serum during a mean follow-up of 663 days. Combination therapy resulted in a dominant, cost-effective strategy with an average cost-effectiveness ratio of $252,111/recurrence prevented compared with $362,570/recurrence prevented in the monotherapy strategy. Combination prophylaxis with HBIG and lamivudine is highly effective in preventing recurrent HBV, may protect against the emergence of resistant mutants, and is significantly more cost-effective than HBIG monotherapy with its associated rate of recurrent HBV.

NCCN Practice Guidelines for Breast Cancer.

The therapeutic options for patients with noninvasive or invasive breast cancer are complex and varied. In many situations, the patient and physician have the responsibility to jointly explore and ultimately select the most appropriate option from among the available alternatives. With rare exception, the evaluation, treatment, and follow-up recommendations contained within these guidelines were based largely on the results of past and present clinical trials. However, there is not a single clinical situation in which the treatment of breast cancer has been optimized with respect to either maximizing cure or minimizing toxicity and disfigurement. Therefore, patient and physician participation in prospective clinical trials allows patients not only to receive state-of-the-art cancer treatment but also to contribute to the improvement of treatment of future patients.

Tumors and DNA adducts in mice exposed to benzo[a]pyrene and coal tars: implications for risk assessment.

Current methods to estimate the quantitative cancer risk of complex mixtures of polycyclic aromatic hydrocarbons (PAH) such as coal tar assume that overall potency can be derived from knowledge of the concentration of a few carcinogenic components such as benzo[a]pyrene (B[a]P). Genotoxic damage, such as DNA adducts, is thought to be an essential aspect of PAH-induced tumorigenesis and could be a biomarker for exposure useful for estimating risk. However, the role of B[a]P and the relationship of adduct formation in tumorigenesis have not been tested rigorously in models appropriate for human health risk assessment. Therefore, we directly compared tumor induction and adduct formation by B[a]P and coal tars in several experimental protocols, including one broadly accepted and used by regulators. We found that B[a]P content did not account for tumor incidences after exposure to coal tars. DNA adducts were found in both tumors and tumor-free tissue and tumor outcomes were not predicted by either quantitation of total DNA adducts or by the DNA adduct formed by B[a]P. These data suggest that risk assessments based on B[a]P content may not predict accurately risk to human health posed by environmental PAH.

A comprehensive assessment of the cost of multiple sclerosis in the United States.

Comprehensive data on the costs of multiple sclerosis is sparse. We conducted a survey of 606 persons with MS who were members of the National Multiple Sclerosis Society to obtain data on their cost of personal health services, other services, equipment, and earnings. Compensation of such cost in the form of health insurance, income support, and other subsidies was measured. Survey data and data from several secondary sources was used to measure costs incurred by comparable persons without MS. Based on the 1994 data, the annual cost of MS was estimated at over $34,000 per person, translating into a conservative estimate of national annual cost of $6.8 billion, and a total lifetime cost per case of $2.2 million. Major components of cost were earnings loss and informal care. Virtually all persons with MS had health insurance, mostly Medicare/Medicaid. Health insurance covered 51 per cent of costs for services, excluding informal care. On average, compensation for earnings loss was 27 per cent. MS is very costly to the individual, health care system, and society. Much of the cost (57 per cent) is in the form of burdens other than personal health care, including earnings loss, equipment and alternations, and formal and informal care. These costs often are not calculated.

North Carolina stroke prevention and treatment facilities survey: rtPA therapy for acute stroke.

BACKGROUND AND PURPOSE: North Carolina is situated in the "stroke belt" region of the United States, an area of the country with a particularly high incidence of cerebrovascular disease. The North Carolina Stroke Prevention and Treatment Facilities Survey was carried out to determine the availabilities of a variety of stroke prevention and treatment services throughout the state. The purpose of the present study was to determine how widely recombinant tissue-type plasminogen activator (rtPA) has been adopted for the treatment of patients with acute ischemic stroke and to determine the characteristics of the medical facilities in the state offering this therapy. METHODS: A single-page survey was mailed to the medical center directors of each inpatient medical facility in North Carolina. Data collected included questions related to the availability of selected basic and advanced diagnostic tests and procedures, stroke prevention and treatment programs and services (community stroke awareness program, acute stroke identification program, acute stroke team, stroke rtPA protocol, stroke care map, neurologist), and facilities (Stroke Acute Care Unit or equivalent). RESULTS: Responses were obtained from all 125 inpatient medical facilities in North Carolina. rtPA stroke protocols were adopted in 54 facilities located in 46 of the state's 100 counties. Seventy-four percent of the state's population resides in counties with hospitals providing rtPA treatment. Compared with facilities not offering rtPA, those with rtPA protocols more commonly sponsored stroke community awareness programs (41% versus 17%, P=0.003) and more frequently had an organized stroke team (31% versus 8%, P=0. 001), used stroke care maps (56% versus 17%, P<0.001), had rapid stroke identification programs (33% versus 6%, P<0.001), or had a Stroke Acute Care Unit or its equivalent (33% versus 7%, P<0.001). Neurologists were available in 78% of the facilities offering rtPA compared with 38% in facilities without rtPA protocols (P<0.001). CONCLUSIONS: These data show that this new therapy for ischemic stroke is potentially available to a high proportion of the state's citizens based on their county of residence. However, other services that may improve outcomes and reduce stroke-related costs (eg, stroke teams, stroke units, care maps) are not being widely used, even in centers providing treatment with rtPA. The simple methodology used in this study is potentially applicable in other states and permits targeting of selected centers for development of stroke treatment capabilities.

Accuracy of ICD-9-CM coding for the identification of patients with acute ischemic stroke: effect of modifier codes.

BACKGROUND AND PURPOSE: Discharge ICD-9-CM (International Classification of Diseases, 9th Revision, Clinical Modification) codes have been used to identify patients with acute stroke for epidemiological, quality of care, and cost studies. The aim of this study was to determine if the accuracy of the primary ICD-9-CM codes for ischemic stroke is improved by modifier codes and how specific codes reflect stroke subtype diagnoses. METHODS: Available hospital charts for all patients discharged from a single hospital between May 1995 and June 1997 with ICD-9-CM codes 433 (occlusion and stenosis of precerebral arteries), 434 (occlusion of cerebral arteries), or 436 (acute but ill-defined cerebrovascular disease) listed in the first position were reviewed. The primary discharge diagnosis was verified, and a presumed stroke subtype was assigned on the basis of information provided in the medical record. RESULTS: Charts were available for 175 of the 198 identified patients (88%). Of these, 61% had an acute ischemic stroke (code 433, 4%; 434, 82%; 436, 79%) with the remaining patients having other conditions. Of the 130 patients with a modifier code indicating cerebral infarction, 79% had an acute stroke; of the 45 patients with a modifier code indicating an absence of cerebral infarction, 7% had acute stroke (sensitivity, 0.97; specificity, 0.60). The codes with the highest proportions of ischemic stroke cases were 434.11 (embolic occlusion of cerebral arteries with infarction, 85%), 434.91 (unspecified occlusion of precerebral arteries with infarction, 82%), and 436 (79%), with a combined sensitivity of 0.81 and specificity of 0.90. On review, 73% of patients with code 434.11 had embolic strokes, and 47% of those with code 436 had an identified stroke cause. Of patients with code 434.91, 39% had stroke of uncertain cause, 25% "lacunar," 17% atherothrombosis, and 15% embolism. CONCLUSIONS: Despite the use of modifier codes, 15% to 20% of patients with the indicated primary ICD-9-CM codes have conditions other than acute ischemic stroke. Although the proportion of patients with acute stroke increased from 61% to 79% with the use of modifier codes, the inclusion of modifier codes did not have an appreciable effect on the accuracy of the coding if patients with code 433 are excluded. Assignment of presumed ischemic stroke subtype is particularly inaccurate.