Gary Schneider - Academia.edu (original) (raw)

Papers by Gary Schneider

Research paper thumbnail of Pregnancy rates and outcomes in women with and without MS in the United States

Neurology, Jan 23, 2018

To compare pregnancy prevalence and complications in women with and without multiple sclerosis (M... more To compare pregnancy prevalence and complications in women with and without multiple sclerosis (MS). This retrospective US administrative claims study used data from January 1, 2006, to June 30, 2015. All data for women with MS were included. A nationally representative 5% random sample from approximately 58 million women without MS was used to compute the dataset. Annual pregnancy rates, identified via diagnosis/procedure codes and adjusted for covariates, were estimated via logistic regression. Claims for pregnancy and labor/delivery complications were compared using propensity score matching. From 2006 to 2014, the adjusted proportion of women with MS and pregnancy increased from 7.91% to 9.47%; the adjusted proportion without MS and with pregnancy decreased from 8.83% to 7.75%. The difference in linear trend (0.17% increase and 0.15% decrease in per-annum pregnancy rates) was significant ( statistic = 7.8; < 0.0001). After matching (n = 2,115 per group), a higher proportion o...

Research paper thumbnail of Anemia as a Predictor of Cardiovascular Events in Patients with Elevated Serum Creatinine

Journal of the American Society of Nephrology, 2006

Patients with anemia and patients with chronic kidney disease have elevated risks for cardiovascu... more Patients with anemia and patients with chronic kidney disease have elevated risks for cardiovascular disease. Available studies have been too small to provide details about the relationship or to provide for extensive covariate control. In a large insurance database with linked laboratory values, records of women with serum creatinine >1.2 mg/dl and men with serum creatinine >1.4 mg/dl, identified from July 2000 through June 2003, were sought, and the insurance claims searches for hospitalizations that were associated with myocardial infarction, coronary revascularization, unstable angina, stroke, or congestive heart failure. New onset of dialysis also was sought. Multivariate Poisson regression was used to estimate rate ratios for these events at various hemoglobin (Hb) levels, with adjustment for patient characteristics and previous event history. Among 88,657 patients with high serum creatinine, the risk for hospitalization with myocardial infarction was two to five times higher in anemic (Hb <12 g/dl) patients than in people with Hb from 12.0 to 12.9 g/dl. A similar but less dramatic pattern of higher incidence of coronary revascularization was observed with lower Hb levels. Risks for hospitalization with congestive heart failure declined regularly with increasing Hb levels from a doubling of risk at Hb <10 g/dl to a 61% decrease at 15 g/dl, both relative to 12.0 to 12.9 g/dl. The risk for progression to dialysis was only slightly elevated (7 to 34%) in anemic patients. Anemia raises the risk for cardiovascular disease in patients with elevated serum creatinine.

Research paper thumbnail of Role of pharmacoepidemiology studies in addressing pharmacovigilance questions: a case example of pancreatitis risk among ulcerative colitis patients using mesalazine

European Journal of Clinical Pharmacology, 2014

Purpose Well-designed pharmacoepidemiology studies address several limitations of postmarketing s... more Purpose Well-designed pharmacoepidemiology studies address several limitations of postmarketing spontaneous reports in regard to signal evaluation. This study evaluated a signal of disproportionate reporting of acute pancreatitis cases observed in patients with ulcerative colitis (UC) treated with MMX Multi Matrix System® (MMX®) mesalazine and demonstrated how inherent limitations of postmarketing reports were overcome. Methods Adults with UC who were new users of MMX mesalazine or another branded mesalazine (controlled-release, delayed-release, or extended-release mesalazine; balsalazide disodium; olsalazine sodium; sulfasalazine; or sulfasalazine delayed-release) were identified from a large US administrative healthcare claims database. Acute pancreatitis incidence rates were compared between patients on MMX mesalazine versus comparator therapies. Propensity scores were used to match patients on MMX mesalazine with patients on comparator drugs to achieve a balance of baseline patient factors. Results Crude incidence rates [95 % confidence interval (CI)] of acute pancreatitis among patients on MMX mesalazine were similar to those of patients on comparator therapies [8.55 (5.54-13.21) vs 10.05 (7.54-13.41) per 1000 person-years]; the resulting incidence rate ratio (IRR) was [0.85 (0.48-1.47)]. Propensity score-matching had little influence on the IRR [0.84 (0.46-1.55)]; nor did further adjustment by demographic characteristics, daily dose, and causes of acute pancreatitis [0.76 (0.41-1.43)]. Conclusion Findings of no increase in pancreatitis risk with MMX mesalazine demonstrate the value of pharmacoepidemiology studies for evaluating a drug's postmarket safety profile when confronted with spontaneous reporting data suggestive of a safety issue.

Research paper thumbnail of Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in the US

Current Medical Research and Opinion, 2014

Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in... more Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in the US Curr Med Res Opin 2014 1-3 Supplemental tables Supplementary Table 1. Definitions of atrial fibrillation and valvular disease. ICD-9 Diagnosis or Procedure Code Description Atrial Fibrillation diagnostic code: 427.31 Atrial fibrillation Valvular diagnostic codes: 394.0 Mitral stenosis 394.2 Mitral stenosis with insufficiency 396.0 Mitral valve stenosis and aortic valve stenosis 396.1 Mitral valve stenosis and aortic valve insufficiency Valvular CPT procedure codes: 33999 Unlisted procedure, cardiac surgery 0257T Implantation of catheter-delivered prosthetic aortic heart valve; open thoracic approach (e.g., transapical, transventricular) 0258T Transthoracic cardiac exposure (e.g., sternotomy, thoracotomy, subxiphoid) for catheter-delivered aortic valve replacement; without cardiopulmonary bypass 0259T Transthoracic cardiac exposure (e.g., sternotomy, thoracotomy, subxiphoid) for catheter-delivered aortic valve replacement; with cardiopulmonary bypass 33405 Replacement, aortic valve, with cardiopulmonary bypass; with prosthetic valve other than homograft or stentless valve 33425 Valvuloplasty, mitral valve, with cardiopulmonary bypass 33426 Valvuloplasty, mitral valve, with cardiopulmonary bypass; with prosthetic ring 33427 Valvuloplasty, mitral valve, with cardiopulmonary bypass; radical reconstruction, with or without ring 33430 Replacement, mitral valve, with cardiopulmonary bypass 0262T Implantation of catheter-delivered prosthetic pulmonary valve, endovascular approach 33475 Replacement, pulmonary valve 33460 Valvectomy, tricuspid valve, with cardiopulmonary bypass 33463 Valvuloplasty, tricuspid valve; without ring insertion 33464 Valvuloplasty, tricuspid valve; with ring insertion 33465 Replacement, tricuspid valve, with cardiopulmonary bypass CPT-Current Procedural Terminology.

Research paper thumbnail of Impact of health care payer type on HIV stage of illness at time of initiation of antiretroviral therapy in the USA

AIDS Care, 2013

There is evidence that earlier initiation of HIV antiretroviral therapy (ART) is associated with ... more There is evidence that earlier initiation of HIV antiretroviral therapy (ART) is associated with better outcomes, including lower morbidity and mortality. Based on recent studies indicating that Medicaid enrollees are more likely to have suboptimal access to medical care, we hypothesized that HIV severity at time of ART initiation is worse for Medicaid patients than patients with other health care coverage. We conducted a US retrospective analysis of GE Centricity Outpatient Electronic Medical Records spanning 1 January 1997 through 30 September 2009. Subjects included all adult HIV patients initiating first-line ART who had CD4+ results within 90 days pre-initiation. HIV stage was defined using CD4 ranges: &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;500 (n=520), 351-500 (n=379), 201-350 (n=580), or ≤200 (n=406) cells/mm(3), with lower CD4 count being indicative of increased disease severity. Payer type was defined as the patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s primary payer: Medicaid, Medicare, commercial insurance, self-pay or other/unknown. After controlling for demographic and clinical covariates, cumulative logit models assessed the effect of payer type on HIV stage at ART initiation. The study included 1885 subjects with the primary payer being Medicaid (n=218), Medicare (n=330), commercial insurance (n=538), self-pay (n=159) or other/unknown (n=640). Final logit models demonstrated that, compared to patients on Medicaid, the odds of initiating ART at a higher CD4 range were significantly greater for those commercially insured (odds ratio [OR]=1.53; P=0.005), self-paying (OR=1.56; P=0.023) and other/unknown (OR=1.79; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and similar for patients enrolled in Medicare (OR=1.11; P=0.521). Medicaid patients initiated ART at a more advanced stage of HIV than patients who were commercially insured, self-paying, or had other/unknown coverage. With HIV treatment guidelines now supporting ART initiation in patients with higher CD4 counts, these findings underscore the need for mitigating barriers, particularly in the Medicaid population, that may delay treatment initiation.

Research paper thumbnail of Pregnancy rates and outcomes in women with and without MS in the United States

Neurology, Jan 23, 2018

To compare pregnancy prevalence and complications in women with and without multiple sclerosis (M... more To compare pregnancy prevalence and complications in women with and without multiple sclerosis (MS). This retrospective US administrative claims study used data from January 1, 2006, to June 30, 2015. All data for women with MS were included. A nationally representative 5% random sample from approximately 58 million women without MS was used to compute the dataset. Annual pregnancy rates, identified via diagnosis/procedure codes and adjusted for covariates, were estimated via logistic regression. Claims for pregnancy and labor/delivery complications were compared using propensity score matching. From 2006 to 2014, the adjusted proportion of women with MS and pregnancy increased from 7.91% to 9.47%; the adjusted proportion without MS and with pregnancy decreased from 8.83% to 7.75%. The difference in linear trend (0.17% increase and 0.15% decrease in per-annum pregnancy rates) was significant ( statistic = 7.8; < 0.0001). After matching (n = 2,115 per group), a higher proportion o...

Research paper thumbnail of Anemia as a Predictor of Cardiovascular Events in Patients with Elevated Serum Creatinine

Journal of the American Society of Nephrology, 2006

Patients with anemia and patients with chronic kidney disease have elevated risks for cardiovascu... more Patients with anemia and patients with chronic kidney disease have elevated risks for cardiovascular disease. Available studies have been too small to provide details about the relationship or to provide for extensive covariate control. In a large insurance database with linked laboratory values, records of women with serum creatinine >1.2 mg/dl and men with serum creatinine >1.4 mg/dl, identified from July 2000 through June 2003, were sought, and the insurance claims searches for hospitalizations that were associated with myocardial infarction, coronary revascularization, unstable angina, stroke, or congestive heart failure. New onset of dialysis also was sought. Multivariate Poisson regression was used to estimate rate ratios for these events at various hemoglobin (Hb) levels, with adjustment for patient characteristics and previous event history. Among 88,657 patients with high serum creatinine, the risk for hospitalization with myocardial infarction was two to five times higher in anemic (Hb <12 g/dl) patients than in people with Hb from 12.0 to 12.9 g/dl. A similar but less dramatic pattern of higher incidence of coronary revascularization was observed with lower Hb levels. Risks for hospitalization with congestive heart failure declined regularly with increasing Hb levels from a doubling of risk at Hb <10 g/dl to a 61% decrease at 15 g/dl, both relative to 12.0 to 12.9 g/dl. The risk for progression to dialysis was only slightly elevated (7 to 34%) in anemic patients. Anemia raises the risk for cardiovascular disease in patients with elevated serum creatinine.

Research paper thumbnail of Role of pharmacoepidemiology studies in addressing pharmacovigilance questions: a case example of pancreatitis risk among ulcerative colitis patients using mesalazine

European Journal of Clinical Pharmacology, 2014

Purpose Well-designed pharmacoepidemiology studies address several limitations of postmarketing s... more Purpose Well-designed pharmacoepidemiology studies address several limitations of postmarketing spontaneous reports in regard to signal evaluation. This study evaluated a signal of disproportionate reporting of acute pancreatitis cases observed in patients with ulcerative colitis (UC) treated with MMX Multi Matrix System® (MMX®) mesalazine and demonstrated how inherent limitations of postmarketing reports were overcome. Methods Adults with UC who were new users of MMX mesalazine or another branded mesalazine (controlled-release, delayed-release, or extended-release mesalazine; balsalazide disodium; olsalazine sodium; sulfasalazine; or sulfasalazine delayed-release) were identified from a large US administrative healthcare claims database. Acute pancreatitis incidence rates were compared between patients on MMX mesalazine versus comparator therapies. Propensity scores were used to match patients on MMX mesalazine with patients on comparator drugs to achieve a balance of baseline patient factors. Results Crude incidence rates [95 % confidence interval (CI)] of acute pancreatitis among patients on MMX mesalazine were similar to those of patients on comparator therapies [8.55 (5.54-13.21) vs 10.05 (7.54-13.41) per 1000 person-years]; the resulting incidence rate ratio (IRR) was [0.85 (0.48-1.47)]. Propensity score-matching had little influence on the IRR [0.84 (0.46-1.55)]; nor did further adjustment by demographic characteristics, daily dose, and causes of acute pancreatitis [0.76 (0.41-1.43)]. Conclusion Findings of no increase in pancreatitis risk with MMX mesalazine demonstrate the value of pharmacoepidemiology studies for evaluating a drug's postmarket safety profile when confronted with spontaneous reporting data suggestive of a safety issue.

Research paper thumbnail of Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in the US

Current Medical Research and Opinion, 2014

Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in... more Characteristics of patients with non-valvular atrial fibrillation using dabigatran or warfarin in the US Curr Med Res Opin 2014 1-3 Supplemental tables Supplementary Table 1. Definitions of atrial fibrillation and valvular disease. ICD-9 Diagnosis or Procedure Code Description Atrial Fibrillation diagnostic code: 427.31 Atrial fibrillation Valvular diagnostic codes: 394.0 Mitral stenosis 394.2 Mitral stenosis with insufficiency 396.0 Mitral valve stenosis and aortic valve stenosis 396.1 Mitral valve stenosis and aortic valve insufficiency Valvular CPT procedure codes: 33999 Unlisted procedure, cardiac surgery 0257T Implantation of catheter-delivered prosthetic aortic heart valve; open thoracic approach (e.g., transapical, transventricular) 0258T Transthoracic cardiac exposure (e.g., sternotomy, thoracotomy, subxiphoid) for catheter-delivered aortic valve replacement; without cardiopulmonary bypass 0259T Transthoracic cardiac exposure (e.g., sternotomy, thoracotomy, subxiphoid) for catheter-delivered aortic valve replacement; with cardiopulmonary bypass 33405 Replacement, aortic valve, with cardiopulmonary bypass; with prosthetic valve other than homograft or stentless valve 33425 Valvuloplasty, mitral valve, with cardiopulmonary bypass 33426 Valvuloplasty, mitral valve, with cardiopulmonary bypass; with prosthetic ring 33427 Valvuloplasty, mitral valve, with cardiopulmonary bypass; radical reconstruction, with or without ring 33430 Replacement, mitral valve, with cardiopulmonary bypass 0262T Implantation of catheter-delivered prosthetic pulmonary valve, endovascular approach 33475 Replacement, pulmonary valve 33460 Valvectomy, tricuspid valve, with cardiopulmonary bypass 33463 Valvuloplasty, tricuspid valve; without ring insertion 33464 Valvuloplasty, tricuspid valve; with ring insertion 33465 Replacement, tricuspid valve, with cardiopulmonary bypass CPT-Current Procedural Terminology.

Research paper thumbnail of Impact of health care payer type on HIV stage of illness at time of initiation of antiretroviral therapy in the USA

AIDS Care, 2013

There is evidence that earlier initiation of HIV antiretroviral therapy (ART) is associated with ... more There is evidence that earlier initiation of HIV antiretroviral therapy (ART) is associated with better outcomes, including lower morbidity and mortality. Based on recent studies indicating that Medicaid enrollees are more likely to have suboptimal access to medical care, we hypothesized that HIV severity at time of ART initiation is worse for Medicaid patients than patients with other health care coverage. We conducted a US retrospective analysis of GE Centricity Outpatient Electronic Medical Records spanning 1 January 1997 through 30 September 2009. Subjects included all adult HIV patients initiating first-line ART who had CD4+ results within 90 days pre-initiation. HIV stage was defined using CD4 ranges: &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;500 (n=520), 351-500 (n=379), 201-350 (n=580), or ≤200 (n=406) cells/mm(3), with lower CD4 count being indicative of increased disease severity. Payer type was defined as the patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s primary payer: Medicaid, Medicare, commercial insurance, self-pay or other/unknown. After controlling for demographic and clinical covariates, cumulative logit models assessed the effect of payer type on HIV stage at ART initiation. The study included 1885 subjects with the primary payer being Medicaid (n=218), Medicare (n=330), commercial insurance (n=538), self-pay (n=159) or other/unknown (n=640). Final logit models demonstrated that, compared to patients on Medicaid, the odds of initiating ART at a higher CD4 range were significantly greater for those commercially insured (odds ratio [OR]=1.53; P=0.005), self-paying (OR=1.56; P=0.023) and other/unknown (OR=1.79; P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001) and similar for patients enrolled in Medicare (OR=1.11; P=0.521). Medicaid patients initiated ART at a more advanced stage of HIV than patients who were commercially insured, self-paying, or had other/unknown coverage. With HIV treatment guidelines now supporting ART initiation in patients with higher CD4 counts, these findings underscore the need for mitigating barriers, particularly in the Medicaid population, that may delay treatment initiation.