Differences In Rates Of Outcomes Research Articles

Perioperative management and outcomes in patients receiving low-dose rivaroxaban and/or aspirin: a subanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial

BackgroundNo study has investigated the perioperative management and clinical outcomes in patients who are receiving rivaroxaban 2.5 mg twice a day and acetylsalicylic acid (ASA) 81 to 100 mg daily. ObjectiveTo assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily. To assess perioperative management and outcomes in patients who are receiving low-dose rivaroxaban, 2.5 mg twice-daily, and low-dose ASA, 81 to 100 mg daily. MethodsSubanalysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial was performed to assess perioperative management and clinical outcomes in patients with stable coronary or peripheral artery disease who were randomized to receive rivaroxaban 2.5 mg twice a day plus ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA 100 mg daily. Patients studied required a surgery/procedure during the trial. The study outcomes, which included myocardial infarction, angina, stroke, acute limb ischemia, bleeding, and death, were assessed according to treatment allocation. ResultsThere were 2632 patients studied (mean age, 68 years; 80% male) who had a surgery/procedure, comprising percutaneous coronary interventions (∼43%), carotid or other arterial angioplasty (∼15%), pacemaker or internal cardiac defibrillator implantation (∼9%), and coronary artery bypass graft surgery (∼7%). Perioperative study drug management varied, with about one-third of patients not interrupting study drug and the remainder interrupting it between 1 and ≥10 days preprocedure. The incidences of adverse outcomes across treatment groups were 12.7% to 15.3% for myocardial ischemia, 0.8% to 1.2% for stroke, 0.1% to 0.2% for venous thromboembolism, and 3.1% to 4.2% for any bleeding. There was no statistically significant difference in outcome rates across treatment groups. ConclusionIn patients in the COMPASS trial who required a surgery/procedure, there was no significant difference in perioperative adverse outcomes whether patients were receiving rivaroxaban 2.5 mg twice a day and ASA 100 mg daily, rivaroxaban 5 mg twice a day, or ASA alone.

Blood Pressure Control Targets and Risk of Cardiovascular and Cerebrovascular Events After Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) survivors are at high risk for recurrent stroke and cardiovascular events. Blood pressure (BP) control represents the most potent intervention to lower these risks, but optimal treatment targets in this patient population remain unknown. We sought to determine whether survivors of ICH achieving more intensive BP control than current guideline recommendations (systolic BP <130 mmHg and diastolic BP <80 mmHg) were at lower risk of major adverse cardiovascular and cerebrovascular events and mortality. We analyzed data for 1828 survivors of spontaneous ICH from 2 cohort studies. Follow-up BP measurements were recorded 3 and 6 months after ICH, and every 6 months thereafter. Outcomes of interest were major adverse cardiovascular and cerebrovascular events (recurrent ICH, incident ischemic stroke, myocardial infarction), vascular mortality (defined as mortality attributed to recurrent ICH, ischemic stroke, or myocardial infarction), and all-cause mortality. During a median follow-up of 46.2 months, we observed 166 recurrent ICH, 68 ischemic strokes, 69 myocardial infarction, and 429 deaths. Compared with survivors of ICH with systolic BP 120 to 129 mmHg, participants who achieved systolic BP <120 mmHg displayed reduced risk of recurrent ICH (adjusted hazard ratio [AHR], 0.74 [95% CI, 0.59-0.94]) and major adverse cardiovascular and cerebrovascular events (AHR, 0.69 [95% CI, 0.53-0.92]). All-cause mortality (AHR, 0.76 [95% CI, 0.57-1.03]) and vascular mortality (AHR, 0.68 [95% CI, 0.45-1.01]) did not differ significantly. Among participants aged >75 years or with modified Rankin Scale score 4 to 5, systolic BP <120 mmHg was associated with increased all-cause mortality (AHR, 1.38 [95% CI, 1.02-1.85] and AHR, 1.36 [95% CI, 1.03-1.78], respectively), but not vascular mortality. We found no differences in outcome rates between survivors of ICH with diastolic BP <70 versus 70 to 79 mmHg. Targeting systolic BP <120 mmHg in select groups of survivors of ICH could result in decreased major adverse cardiovascular and cerebrovascular events risk without increasing mortality. Our findings warrant investigation in dedicated randomized controlled trials.

Assessment of Regional Variability in COVID-19 Outcomes Among Patients With Cancer in the United States

The COVID-19 pandemic has had a distinct spatiotemporal pattern in the United States. Patients with cancer are at higher risk of severe complications from COVID-19, but it is not well known whether COVID-19 outcomes in this patient population were associated with geography. To quantify spatiotemporal variation in COVID-19 outcomes among patients with cancer. This registry-based retrospective cohort study included patients with a historical diagnosis of invasive malignant neoplasm and laboratory-confirmed SARS-CoV-2 infection between March and November 2020. Data were collected from cancer care delivery centers in the United States. Patient residence was categorized into 9 US census divisions. Cancer center characteristics included academic or community classification, rural-urban continuum code (RUCC), and social vulnerability index. The primary outcome was 30-day all-cause mortality. The secondary composite outcome consisted of receipt of mechanical ventilation, intensive care unit admission, and all-cause death. Multilevel mixed-effects models estimated associations of center-level and census division-level exposures with outcomes after adjustment for patient-level risk factors and quantified variation in adjusted outcomes across centers, census divisions, and calendar time. Data for 4749 patients (median [IQR] age, 66 [56-76] years; 2439 [51.4%] female individuals, 1079 [22.7%] non-Hispanic Black individuals, and 690 [14.5%] Hispanic individuals) were reported from 83 centers in the Northeast (1564 patients [32.9%]), Midwest (1638 [34.5%]), South (894 [18.8%]), and West (653 [13.8%]). After adjustment for patient characteristics, including month of COVID-19 diagnosis, estimated 30-day mortality rates ranged from 5.2% to 26.6% across centers. Patients from centers located in metropolitan areas with population less than 250 000 (RUCC 3) had lower odds of 30-day mortality compared with patients from centers in metropolitan areas with population at least 1 million (RUCC 1) (adjusted odds ratio [aOR], 0.31; 95% CI, 0.11-0.84). The type of center was not significantly associated with primary or secondary outcomes. There were no statistically significant differences in outcome rates across the 9 census divisions, but adjusted mortality rates significantly improved over time (eg, September to November vs March to May: aOR, 0.32; 95% CI, 0.17-0.58). In this registry-based cohort study, significant differences in COVID-19 outcomes across US census divisions were not observed. However, substantial heterogeneity in COVID-19 outcomes across cancer care delivery centers was found. Attention to implementing standardized guidelines for the care of patients with cancer and COVID-19 could improve outcomes for these vulnerable patients.

Abstract 13730: In-Hospital Outcomes for Takotsubo Cardiomyopathy Among Patients With Psychiatric Diagnosis

Background: Takotsubo (or stress) cardiomyopathy (TC) is a transient regional systolic dysfunction, clinically and echocardiographically resembling acute coronary syndrome (ACS) in the absence of obstructive coronary artery disease. The prevalence of psychiatric disorders is high in TC. However, it is unclear whether presence of underlying psychiatric condition impacts outcomes of TC. Methods: Hospitalizations for TC from 2012 to 2018 were identified using the National Inpatient Sample (NIS) and stratified by presence or absence of concomitant psychiatric diagnoses (major depression, dysthymia, anxiety, bipolar, substance abuse). Outcomes of interest included mortality, cardiac arrest, cardiogenic shock, intra-aortic balloon pump (IABP), mechanical ventilation, and length of stay. Differences in outcome rates were compared using the Rao-Scott chi-square test; length of stay was compared using a lognormal regression model. All analyses accounted for the NIS sampling design. Results: A total of 51,625 hospital discharges with TC were identified, of which 21,690 (42%) carried a psychiatric diagnosis. There were no statistically significant differences in mortality (1.2% vs. 1.6%; p=0.087), cardiac arrest (1.5% vs. 1.5%; p=0.853), cardiogenic shock (4.6% vs. 4.9%; p=0.427), IABP use (1.6% vs. 1.7%; p=0.695), mechanical ventilation (4.9% vs. 4.2%; p=0.113) for patients with and without psychiatric diagnosis, respectively. The length of stay among patients with psychiatric diagnosis, was marginally higher (median 3.7, IQR [3.6-3.8] days vs. 3.5 [3.4-3.6] days; p&lt;0.01). Conclusion: Our analysis demonstrates that in-hospital mortality and complications of TC patients with and without psychiatric illness are statistically similar.

Clozapine treatment and risk of severe COVID-19 infection.

ObjectiveTo investigate whether patients with clozapine treatment are at an increased risk of a more severe COVID‐19 infection as compared with patients on other antipsychotic drugs.MethodsIn this register‐based cohort study, all residents (age 18 or older) in the Stockholm Region with a psychotic disorder diagnosis and antipsychotic treatment were included (N = 8 233) and followed from 1 March 2020 to 14 January 2021. The exposure was defined as clozapine treatment and the outcome measures (indicating a more severe COVID‐19 infection) were: inpatient care, care within intensive care unit or death due to COVID‐19 infection. Differences in outcome rates between exposed (n = 966) and unexposed (other antipsychotics; n = 7 267) were examined using Cox proportional hazards models and expressed as hazard ratios (HR) with 95% confidence intervals (CI).ResultsNo statistically significant differences in outcome rates were found between the two groups of patients after adjusting for age, sex and residence in retirement homes. The adjusted HR for the exposed compared to the unexposed was 0.96 (95% CI: 0.54, 1.70) for inpatient care; 1.69 (0.48, 5.93) for care in intensive care unit (ICU); and 0.86 (0.26, 2.80) for death. Regarding inpatient care, additional adjusting for country of birth, living in socioeconomically vulnerable areas, number of care visits during the previous year, and comorbid medical illnesses did not alter the results.ConclusionsOur results may add support to the present guidelines, recommending sustained clozapine treatment during the current COVID‐19 pandemic with careful monitoring and readiness to alter drug doses as needed.

Diuretic therapy as prognostic enrichment factor for clinical trials in patients with heart failure with reduced ejection fraction.

Loop diuretics are the mainstay of congestion treatment in patients with heart failure (HF). We assessed the association between baseline loop diuretic use and outcome. We also compared the increment in risk related to diuretic dose with conventional prognostic enrichment criteria used in the EMPHASIS-HF trial, which included patients with systolic HF and mild symptoms, such as prior hospitalization and elevated natriuretic peptides. Individual analyses were performed according to baseline loop diuretic usage (furosemide-equivalent dose > 40mg, 1-40mg, and no furosemide), and according to enrichment criteria adopted in the trial [i.e. recent hospitalization (< 30days or 30 to 180days prior to randomization) due to HF or other cardiovascular cause, or elevated natriuretic peptides]. The primary endpoint was a composite of cardiovascular death or HF hospitalization. Loop diuretic usage at baseline (HR for > 40mg furosemide-equivalent dose = 3.16, 95% CI 2.43-4.11; HR for 1-40mg = 2.06, 95% CI 1.60-2.65) was significantly associated with a higher risk for the primary endpoint in a stepwise manner when compared to no baseline loop diuretic usage. In contrast, the differences in outcome rates were more modest when using history of hospitalization and/or BNP: all HR ranged from 1 (reference, non-HF related CV hospitalization > 30days) to 2.04 (HF hospitalization < 30days). The effect of eplerenone on the primary endpoint was consistent across subgroups in both analyses (P for interaction ≥ 0.2 for all). Loop diuretic usage (especially at doses > 40mg) identified patients at higher risk than history of HF hospitalization and/or high BNP blood concentrations.

COVID-19 Outcomes in Individuals with Sickle Cell Disease and Sickle Cell Trait Compared to Blacks without Sickle Cell Disease or Trait

Introduction: By August 1, 2020 in the United States, more than 3 million cases of Coronavirus disease 2019 (COVID-19) had been reported with more than 150,000 deaths due to this disease. Growing evidence suggests that individuals with the pre-existing conditions of hypertension, diabetes, cardiovascular disease and obesity are at a higher risk of more serious COVID-19 illness. However, the impact of COVID-19 on individuals with sickle cell disease and sickle cell trait as compared to those without sickle cell disease or trait is not known. The objective of this study was to determine the rate of hospitalization, disease symptoms and deaths due to COVID-19, in patients with sickle cell disease and sickle cell trait compared to Blacks without sickle cell disease or trait.Methods: We leveraged existing electronic health record (EHR) data from multiple sites that contribute data to a research network, TriNetX. TriNetX query platform was used to identify patients with COVID-19 infection based on ICD diagnoses codes or a positive COVID-19 result from a nucleic acid amplification with probe-based detection test, present any time after January 20, 2020 (this is when the first COVID-19 case was detected in the United States) within the patients’ EHR data. We report rates of specific COVID-19 related outcomes among individuals with sickle cell disease and trait, calculated as % of patients in cohort with the particular outcome. Our outcomes of interest included COVD-19 related symptoms, hospitalization, and death, which occurred within 2 weeks of COVID diagnosis. We used propensity score matching (greedy nearest-neighbor matching algorithm with a caliper of 0.1 pooled standard deviations) to create balanced cohorts for comparing outcomes between individuals with sickle cell disease or trait and Blacks without sickle cell disease or trait. Risk ratios and risk differences are reported along with 95% confidence intervals. Given multiple outcomes of interest, we considered a more stringent two-sided alpha of less than <0.01, based on a z-test, to determine statistical significance for differences in outcome rates.Results: As of July 15, 2020, there were 122 COVID-19 patients who had sickle cell disease and 172 COVID-19 patients who had sickle cell trait. Our comparator groups included 15,762 Blacks who were diagnosed with COVID-19 but did not have sickle cell trait/disease. COVID-19 patients with sickle cell disease were significantly younger and a higher proportion had asthma, type 1 diabetes and pre-existing liver conditions compared to Blacks without sickle cell trait/disease (Table 1). COVID-19 patients with sickle cell trait were significantly younger, a higher proportion were females, overweight/obese, and a higher proportion had asthma or type 1 diabetes compared to Blacks without sickle cell trait/disease (Table 1). The rate of respective outcomes for the three groups is shown in Figure 1. Propensity score matching yielded a cohort of patients such that there were no significant differences in demographic and clinical characteristics between patients with sickle cell disease/trait compared to Blacks without sickle cell trait/disease. After matching, COVID patients with sickle cell disease remained at a higher risk of hospitalization, pneumonia and pain compared to Blacks without sickle cell trait/disease (Table 2). The case fatality rates were not significantly different between those with sickle cell disease compared to Blacks. There were no significant differences in COVID outcomes between sickle cell trait and Blacks without sickle cell trait/disease, within the matched cohort.Conclusions: These data provide evidence that sickle cell disease imposes additional risk of severe COVID-19 illness and hospitalization, after balancing for age, gender and other preexisting conditions. The death rate between sickle cell disease and Blacks without sickle cell trait/disease was not significantly different. There are no significant differences in COVID-19 outcomes between sickle cell trait and Blacks without sickle cell trait/disease, after balancing for age, gender and other pre-existing conditions.DisclosuresBrandow:NIH / NHLBI: Research Funding; Greater Milwaukee Foundation: Research Funding. Panepinto:HRSA: Research Funding; NINDS: Research Funding; NINDS: Research Funding; NHLBI: Research Funding.

Efficacy and safety of vedolizumab in ulcerative colitis in patients from Asian countries in the GEMINI 1 study.

Background/AimsThe efficacy and safety of vedolizumab in moderate to severely active ulcerative colitis (UC) have been demonstrated in the GEMINI 1 study (NCT00783718). This post-hoc exploratory analysis sought to establish the efficacy and safety of vedolizumab in a subgroup of patients from Asian countries with UC from GEMINI 1.MethodsEfficacy outcomes of interest were clinical response, clinical remission and mucosal healing at week 6 (induction phase); and clinical remission, durable clinical response, durable clinical remission, mucosal healing and glucocorticoid-free remission at week 52 (maintenance phase). Differences in outcome rates between vedolizumab and placebo in Asian countries (Hong Kong, India, Malaysia, Singapore, South Korea, and Taiwan) were assessed using descriptive analyses, and efficacy and safety compared between Asian and non-Asian countries.ResultsDuring induction, in Asian countries (n = 58), clinical response rates at week 6 with vedolizumab and placebo were 55.2% and 24.1%, respectively (difference 31.0%; 95% confidence interval: 7.2%–54.9%). In non-Asian countries (n = 316), response rates at week 6 with vedolizumab and placebo were 45.9% and 25.8%, respectively. During maintenance, in Asian countries, clinical remission rates at 52 weeks with vedolizumab administered every 8 weeks, vedolizumab administered every 4 weeks and placebo were 9.1%, 36.8%, and 31.6%, respectively; corresponding rates for mucosal healing were 45.5%, 47.4%, and 47.4%, respectively. Vedolizumab was well-tolerated; adverse event frequency was comparable in Asian and non-Asian countries.ConclusionsIn patients from Asian countries, the efficacy and safety of vedolizumab in treatment of UC were broadly consistent with that in the overall study population.

A collaborative, individual-level analysis compared longitudinal outcomes across the International Network of Chronic Kidney Disease (iNETCKD) cohorts

Rates of chronic kidney disease (CKD) progression, end stage kidney disease (ESKD), all-cause mortality, and cardiovascular (CVD) events among individuals with CKD vary widely across countries. Well-characterized demographic, comorbidity, and laboratory markers captured for prospective cohorts may explain, in part, such differences. To investigate whether core characteristics of individuals with CKD explain differences in rates of outcomes, we conducted an individual-level analysis of eight studies that are part of iNET-CKD, an international network of CKD cohort studies. Overall, the rate of CKD progression was 40 events/1000 person-year (95% confidence interval 39 - 41), 28 (27 - 29) for ESKD, 41 (40 - 42) for death, and 29 (28 - 30) for CVD events. However, standardized rates were highly heterogeneous across studies (over 92.5%). Interactions by study group on the association between baseline characteristics and outcomes were then identified. For example, the adjusted hazard ratio for CKD progression was 0.44 (95% confidence interval 0.35 - 0.56) for women vs. men among the Japanese (CKD-JAC), while it was 0.66 (0.59 - 0.75) among the Uruguayan (NRHP). The adjusted hazard ratio for ESKD was 2.02 (95% CI 1.88 - 2.17) per 10 units lower baseline eGFR among Americans (CRIC), while it was 3.01 (2.57 - 3.53) among Canadians (CanPREDDICT) (significant interaction for comparisons across all studies). The risks of CKD progression, ESKD, death, and CVD vary across countries even after accounting for the distributions of age, sex, comorbidities, and laboratory markers. Thus, our findings support the need for a better understanding of specific factors in different populations that explain this variation.

Does Prescription Opioid Shopping Increase Overdose Rates in Medicaid Beneficiaries?

The link between prescription opioid shopping and overdose events is poorly understood. We test the hypothesis that a history of prescription opioid shopping is associated with increased risk of overdose events. This is a secondary analysis of a linked claims and controlled substance dispense database. We studied adult Medicaid beneficiaries in 2014 with prescription opioid use in the 6 months before an ambulatory care or emergency department visit with a pain-related diagnosis. The primary outcome was a nonfatal overdose event within 6 months of the cohort entry date. The exposure of interest (opioid shopping) was defined as having opioid prescriptions by different prescribers with greater than or equal to 1-day overlap and filled at 3 or more pharmacies in the 6 months before cohort entry. We used a propensity score to match shoppers with nonshoppers in a 1:1 ratio. We calculated the absolute difference in outcome rates between shoppers and nonshoppers. We studied 66,328 patients, including 2,571 opioid shoppers (3.9%). There were 290 patients (0.4%) in the overall cohort who experienced a nonfatal overdose. In unadjusted analyses, shoppers had higher event rates than nonshoppers (rate difference of 4.4 events per 1,000; 95% confidence interval 0.8 to 7.9). After propensity score matching, there were no outcome differences between shoppers and nonshoppers (rate difference of 0.4 events per 1,000; 95% confidence interval -4.7 to 5.5). These findings were robust to various definitions of opioid shoppers and look-back periods. Prescription opioid shopping is not independently associated with increased risk of overdose events.

231 Does Prescription Opioid Shopping Increase Mortality and Overdose Rates?

Prescription opioid shopping is prevalent in emergency department settings. Prescription monitoring and payer “lock-in” programs are increasingly targeting prescription opioid shoppers. However, the link between shopping and overdose events is poorly understood. We studied adult Washington State Medicaid beneficiaries with prescription opioid use in the six months prior to an ambulatory care or emergency department visit with a pain-related diagnosis. The study time frame was Jan 1, 2014 to Dec 31, 2014. We obtained Medicaid claims data linked with controlled substance dispense data from the state prescription monitoring program. The primary outcome was combined all-cause mortality and non-fatal overdose events within six months after the index visit. The exposure of interest (opioid shopping) was defined as having ≥3 prescribers or ≥3 pharmacies in the 6 months prior to the index visit. We used a propensity score to match shoppers with non-shoppers in a 1:1 ratio. The propensity score was calculated based on 40 variables including demographic characteristics, physical and mental health co-morbidities, and measures of prior opioid use. We calculated the absolute difference in outcome rates between shoppers and non-shoppers. We studied 98,684 patients, including 14,701 (14.9%) opioid shoppers. In unadjusted analyses, shoppers had higher event rates than non-shoppers (rate difference of 2.1 events per 1000; 95% CI: 0.8 to 3.5). After 1:1 propensity score matching, there were minimal differences (absolute standardized difference <0.1) between opioid shoppers and matched non-shoppers for all covariates. After propensity score matching, there were no outcome differences between shoppers and non-shoppers (rate difference of -0.7 events per 1000; 95% CI:-3.0 to 1.6). These findings were robust to various definitions of opioid shopping. Prescription opioid shopping is not independently associated with increased risk of death or non-fatal overdose events, and may be a marker of drug diversion. Efforts to improve outcomes among prescription opioid recipients should focus on other validated predictors of overdose risk.

Power of the test: A valuable biostatistical function to validate our research work

Any study involving a sample from population of interest may fail to detect the real significant difference in outcome between the groups being studied. The main reason for its failure may include a poorly designed study or a study that lacked power. This article will briefly summarize the concept of power of study which is necessary to validate clinical research work, wherein differences in outcome rates between the groups under a study are not very large.

Safety of Uninterrupted Warfarin Therapy in Patients Undergoing Cardiovascular Endovascular Procedures: A Systematic Review and Meta-Analysis.

To conduct a systematic review and meta-analysis of complication rates and outcomes in patients undergoing endovascular procedures who receive uninterrupted versus interrupted warfarin therapy. Literature published between 1990 and 2014 was searched for reports of comparative studies of vascular procedures. Information on periprocedural complications and patient deaths less than 30 days after the procedure was extracted. A random effects model was used and odds ratios (ORs) were reported. An OR of less than 1 was considered to indicate lower risk of the outcome with uninterrupted warfarin therapy. Meta-analysis was conducted by using meta-analysis software. A total of 27 studies of 20,376 patients were included. For arterial procedures, there were no significant differences between the uninterrupted and interrupted warfarin therapy groups in access site hematoma (OR, 0.59; 95% confidence interval [CI]: 0.33, 1.03; P = .06), any bleeding complications (OR, 0.56; 95% CI: 0.30, 1.06; P = .07), mortality (OR, 1.40; 95% CI: 0.37, 5.25; P = .62), intracranial hemorrhage (OR, 0.55; 95% CI: 0.03, 8.91; P = .68), ischemic stroke (OR, 0.85; 95% CI: 0.12, 5.84; P = .87), and major bleeding (OR, 0.56; 95% CI: 0.21, 1.51; P = .25). For venous procedures, uninterrupted warfarin was associated with lower odds of access site hematoma (OR, 0.70; 95% CI: 0.50, 0.99; P = .04), any bleeding complications (OR, 0.61; 95% CI: 0.48, 0.77; P < .01), ischemic stroke (OR, 0.21; 95% CI: 0.10, 0.45; P < .01), and major bleeding (OR, 0.64; 95% CI: 0.51, 0.80; P < .01). For arterial and venous procedures combined, uninterrupted warfarin was associated with lower odds of access site hematoma (OR, 0.68; 95% CI: 0.51, 0.91; P = .01), bleeding complications (OR, 0.59; 95% CI: 0.48, 0.74; P < .01), ischemic stroke (OR, 0.25; 95% CI: 0.12, 0.50; P < .01), and major bleeding (OR, 0.61; 95% CI: 0.49, 0.77; P < .01). Heterogeneity in most analyses was low, and confidence in the estimates was moderate. Uninterrupted perioperative warfarin therapy is safe for patients undergoing arterial procedures, but interrupted warfarin may be preferred for those undergoing venous procedures; no differences in outcome rates were found in the randomized controlled trials. Future studies should be performed to validate these results.

Race and Mortality Revisited.

In an article in the January/February 2000 issue of Society titled “Race and Mortality,” I explained the statistical pattern, inherent in other than highly irregular risk distributions, whereby the rarer an outcome, the greater tends to be the relative (percentage) difference between the rates at which advantaged and disadvantaged groups experience the outcome and the smaller tends to be the relative difference between rates at which such groups avoid the outcome. By way of example with respect to the health and healthcare outcomes on which the article principally focused, as mortality declines, relative differences in mortality tend to increase while relative differences in survival tend to decrease; as healthcare generally improves, relative differences in receipt of appropriate care tend to decrease while relative differences in failing to receive such care tend to increase. In 2000, however, this pattern was virtually unknown to health disparities researchers or anyone else examining demographic differences in favorable or adverse outcomes. Consequently, most efforts to appraise demographic differences in such outcomes were fundamentally unsound. This article addresses the extent to which the appraisal of demographic differences in outcome rates is any sounder today than it was in 2000. In summary, while there has been increasing recognition of the ways that relative differences in outcome rates tend to be systematically affected by the prevalence (frequency) of an outcome, that recognition has yet to affect the way observers analyze group differences in outcome rates in any context. Though today vastly greater resources are devoted to the study of disparities in health and healthcare outcomes than in 2000, almost nothing said about such things as whether those disparities have increased or decreased over time or are otherwise larger in one setting than another, or even whether a disparity should be deemed large or small, has had a sound statistical basis. Meanwhile, federal regulators encourage mortgage lenders and public schools to reduce the frequency of adverse borrowing and student discipline outcomes in order to reduce the commonly observed severalfold racial and ethnic differences in rates of experiencing those outcomes. Neither the regulators, the congressional committees monitoring regulator policies, nor the institutions reducing the frequency of those outcomes in response to federal encouragements understand that reducing any outcome tends to increase, not reduce, relative differences in experiencing it. More broadly, events since 2000 do little to bolster one’s faith in the validity of accepted scholarship or the capability of individuals or institutions to recognize and acknowledge that things they have been doing for decades or generations have been incorrect or misleading.

PROTOCOL: Systematic Review Protocol: Later School Start Times for Supporting the Education, Health and Well‐being of High School Students

PROTOCOL: Systematic Review Protocol: Later School Start Times for Supporting the Education, Health and Well‐being of High School Students

Enough is enough! Patients who do not conceive on 600 IU/d of gonadotropins show no improvement from an additional 150 IU of LH activity

Studies have suggested that supplemental LH improves outcomes in assisted reproductive technology (ART) cycles. In this retrospective review, an additional 150 IU of LH activity did not improve ART outcomes in women undergoing a second round of IVF/ intracytoplasmic sperm injection (ICSI) after an initial failed cycle using 600 IU of gonadotropins.

Considerations of sample size in medical research

Considerations of sample size in medical research