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1.
Breast Cancer Res Treat ; 201(1): 117-126, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37326764

ABSTRACT

PURPOSE: Studies comparing the effect of aromatase inhibitor (AI) and tamoxifen use on cardiovascular disease (CVD) risk factors in hormone receptor-positive breast cancer (BC) survivors report conflicting results. We examined associations of endocrine therapy use with incident diabetes, dyslipidemia, and hypertension. METHODS: The Pathways Heart Study examines cancer treatment exposures with CVD-related outcomes in Kaiser Permanente Northern California members with BC. Electronic health records provided sociodemographic and health characteristics, BC treatment, and CVD risk factor data. Hazard ratios (HR) and 95% confidence intervals (CI) of incident diabetes, dyslipidemia, and hypertension in hormone receptor-positive BC survivors using AIs or tamoxifen compared with survivors not using endocrine therapy were estimated using Cox proportional hazards regression models adjusted for known confounders. RESULTS: In 8985 BC survivors, mean baseline age and follow-up time was 63.3 and 7.8 years, respectively; 83.6% were postmenopausal. By treatment, 77.0% used AIs, 19.6% used tamoxifen, and 16.0% used neither. Postmenopausal women who used tamoxifen had an increased rate (HR 1.43, 95% CI 1.06-1.92) of developing hypertension relative to those who did not use endocrine therapy. Tamoxifen use was not associated with incident diabetes, dyslipidemia, or hypertension in premenopausal BC survivors. Postmenopausal AI users had higher hazard rates of developing diabetes (HR 1.37, 95% CI 1.05-1.80), dyslipidemia (HR 1.58, 95% CI 1.29-1.92), and hypertension (HR 1.50, 95% CI 1.24-1.82) compared with non-endocrine therapy users. CONCLUSION: Hormone receptor-positive BC survivors treated with AIs may have higher rates of developing diabetes, dyslipidemia, and hypertension over an average 7.8 years post-diagnosis.


Subject(s)
Breast Neoplasms , Hypertension , Female , Humans , Breast Neoplasms/complications , Breast Neoplasms/drug therapy , Breast Neoplasms/epidemiology , Antineoplastic Agents, Hormonal/adverse effects , Cardiometabolic Risk Factors , Tamoxifen/adverse effects , Hypertension/epidemiology , Aromatase Inhibitors/adverse effects , Risk Factors
2.
J Vasc Surg ; 78(5): 1239-1247.e4, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37406943

ABSTRACT

OBJECTIVE: The results of current prospective trials comparing the effectiveness of carotid endarterectomy (CEA) vs standard medical therapy for long-term stroke prevention in patients with asymptomatic carotid stenosis (ACS) will not be available for several years. In this study, we compared the observed effectiveness of CEA and standard medical therapy vs standard medical therapy alone to prevent ipsilateral stroke in a contemporary cohort of patients with ACS. METHODS: This cohort study was conducted in a large integrated health system in adult subjects with 70% to 99% ACS (no neurologic symptom within 6 months) with no prior ipsilateral carotid artery intervention. Causal inference methods were used to emulate a conceptual randomized trial using data from January 1, 2008, through December 31, 2017, for comparing the event-free survival over 96 months between two treatment strategies: (1) CEA within 12 months from cohort entry vs (2) no CEA (standard medical therapy alone). To account for both baseline and time-dependent confounding, inverse probability weighting estimation was used to derive adjusted hazard ratios, and cumulative risk differences were assessed based on two logistic marginal structural models for counterfactual hazards. Propensity scores were data-adaptively estimated using super learning. The primary outcome was ipsilateral anterior ischemic stroke. RESULTS: The cohort included 3824 eligible patients with ACS (mean age: 73.7 years, 57.9% male, 12.3% active smokers), of whom 1467 underwent CEA in the first year, whereas 2297 never underwent CEA. The median follow-up was 68 months. A total of 1760 participants (46%) died, 445 (12%) were lost to follow-up, and 158 (4%) experienced ipsilateral stroke. The cumulative risk differences for each year of follow-up showed a protective effect of CEA starting in year 2 (risk difference = 1.1%, 95% confidence interval: 0.5%-1.6%) and persisting to year 8 (2.6%, 95% confidence interval: 0.3%-4.8%) compared with patients not receiving CEA. CONCLUSIONS: In this contemporary cohort study of patients with ACS using rigorous analytic methodology, CEA appears to have a small but statistically significant effect on stroke prevention out to 8 years. Further study is needed to appropriately select the subset of patients most likely to benefit from intervention.


Subject(s)
Carotid Stenosis , Delivery of Health Care, Integrated , Endarterectomy, Carotid , Stroke , Humans , Male , Aged , Female , Constriction, Pathologic/complications , Cohort Studies , Risk Factors , Treatment Outcome , Carotid Stenosis/complications , Carotid Stenosis/diagnostic imaging , Carotid Stenosis/therapy , Endarterectomy, Carotid/adverse effects , Carotid Arteries , Stroke/diagnosis , Stroke/etiology , Stroke/prevention & control , Risk Assessment
3.
Pharmacoepidemiol Drug Saf ; 32(2): 93-106, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36349471

ABSTRACT

Real-world evidence used for regulatory, payer, and clinical decision-making requires principled epidemiology in design and analysis, applying methods to minimize confounding given the lack of randomization. One technique to deal with potential confounding is propensity score (PS) analysis, which allows for the adjustment for measured preexposure covariates. Since its first publication in 2009, the high-dimensional propensity score (hdPS) method has emerged as an approach that extends traditional PS covariate selection to include large numbers of covariates that may reduce confounding bias in the analysis of healthcare databases. hdPS is an automated, data-driven analytic approach for covariate selection that empirically identifies preexposure variables and proxies to include in the PS model. This article provides an overview of the hdPS approach and recommendations on the planning, implementation, and reporting of hdPS used for causal treatment-effect estimations in longitudinal healthcare databases. We supply a checklist with key considerations as a supportive decision tool to aid investigators in the implementation and transparent reporting of hdPS techniques, and to aid decision-makers unfamiliar with hdPS in the understanding and interpretation of studies employing this approach. This article is endorsed by the International Society for Pharmacoepidemiology.


Subject(s)
Propensity Score , Humans , Bias , Pharmacoepidemiology , Electronic Health Records , Routinely Collected Health Data
4.
Clin Infect Dis ; 72(11): 1900-1909, 2021 06 01.
Article in English | MEDLINE | ID: mdl-32785640

ABSTRACT

BACKGROUND: Persons living with human immunodeficiency virus (HIV; PLWH) experience a high burden of cancer. It remains unknown which cancer types are reduced in PLWH with earlier initiation of antiretroviral therapy (ART). METHODS: We evaluated AIDS-free, ART-naive PLWH during 1996-2014 from 22 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. PLWH were followed from first observed CD4 of 350-500 cells/µL (baseline) until incident cancer, death, lost-to-follow-up, or December 2014. Outcomes included 6 cancer groups and 5 individual cancers that were confirmed by chart review or cancer registry linkage. We evaluated the effect of earlier (in the first 6 months after baseline) versus deferred ART initiation on cancer risk. Marginal structural models were used with inverse probability weighting to account for time-dependent confounding and informative right-censoring, with weights informed by subject's age, sex, cohort, baseline year, race/ethnicity, HIV transmission risk, smoking, viral hepatitis, CD4, and AIDS diagnoses. RESULTS: Protective results for earlier ART were found for any cancer (adjusted hazard ratio [HR] 0.57; 95% confidence interval [CI], .37-.86), AIDS-defining cancers (HR 0.23; 95% CI, .11-.49), any virus-related cancer (HR 0.30; 95% CI, .16-.54), Kaposi sarcoma (HR 0.25; 95% CI, .10-.61), and non-Hodgkin lymphoma (HR 0.22; 95% CI, .06-.73). By 15 years, there was also an observed reduced risk with earlier ART for virus-related NADCs (0.6% vs 2.3%; adjusted risk difference -1.6; 95% CI, -2.8, -.5). CONCLUSIONS: Earlier ART initiation has potential to reduce the burden of virus-related cancers in PLWH but not non-AIDS-defining cancers (NADCs) without known or suspected viral etiology.


Subject(s)
Acquired Immunodeficiency Syndrome , HIV Infections , Neoplasms , Sarcoma, Kaposi , CD4 Lymphocyte Count , HIV , HIV Infections/complications , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Neoplasms/epidemiology
5.
Am J Epidemiol ; 190(7): 1414-1423, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33565574

ABSTRACT

Observational studies reporting on adjusted associations between childhood body mass index (BMI; weight (kg)/height (m)2) rebound and subsequent cardiometabolic outcomes have often not paid explicit attention to causal inference, including definition of a target causal effect and assumptions for unbiased estimation of that effect. Using data from 649 children in a Boston, Massachusetts-area cohort recruited in 1999-2002, we considered effects of stochastic interventions on a chosen subset of modifiable yet unmeasured exposures expected to be associated with early (

Subject(s)
Algorithms , Body Mass Index , Causality , Likelihood Functions , Observational Studies as Topic/methods , Adolescent , Boston , Child, Preschool , Cohort Studies , Female , Humans , Male , Stochastic Processes
6.
J Gen Intern Med ; 36(1): 154-161, 2021 01.
Article in English | MEDLINE | ID: mdl-33001334

ABSTRACT

BACKGROUND: Mail order pharmacy (MOP) use has been linked to improved medication adherence and health outcomes among patients with diabetes. However, no large-scale intervention studies have assessed the effect of encouraging MOP use on medication adherence. OBJECTIVE: To assess an intervention to encourage MOP services to increase its use and medication adherence. DESIGN: Randomized encouragement trial. PATIENTS: 63,012 diabetes patients from three health care systems: Kaiser Permanente Northern California (KPNC), Kaiser Permanente Hawaii (KPHI), and Harvard Pilgrim Health Care (HPHC) who were poorly adherent to at least one class of cardiometabolic medications and had not used MOP in the prior 12 months. INTERVENTION: Patients were randomized to receive either usual care (control arm) or outreach encouraging MOP use consisting of a mailed letter, secure email message, and automated telephone call outlining the potential benefits of MOP use (intervention arm). HPHC intervention patients received the letter only. MEASUREMENTS: We compared the percentages of patients that began using MOP and that became adherent to cardiometabolic medication classes during a 12-month follow-up period. We also conducted a race/ethnicity-stratified analysis. RESULTS: During follow-up, 10.6% of intervention patients began using MOP vs. 9.3% of controls (p < 0.01); the percent of cardiometabolic medication delivered via mail was 42.1% vs. 39.8% (p < 0.01). Metformin adherence improved in the intervention arm relative to control at the two KP sites (52% vs. 49%, p < 0.01). Stratified analyses suggested a significant positive effect of the intervention in White (RR: 1.12, 95% CI: 1.03, 1.22) and Asian (RR: 1.30, 95% CI: 1.17, 1.45) patients. CONCLUSION: This pragmatic trial showed that simple outreach to encourage MOP modestly increased its use and improved adherence measured by refills to a key class of diabetes medications in some settings. Given its minimal cost, clinicians and health systems should consider outreach interventions to actively promote MOP use among diabetes patients. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT02621476.


Subject(s)
Diabetes Mellitus , Pharmacy , Diabetes Mellitus/drug therapy , Diabetes Mellitus/epidemiology , Hawaii/epidemiology , Humans , Medication Adherence , Postal Service
7.
Biometrics ; 77(1): 329-342, 2021 03.
Article in English | MEDLINE | ID: mdl-32297311

ABSTRACT

In studies based on electronic health records (EHR), the frequency of covariate monitoring can vary by covariate type, across patients, and over time, which can limit the generalizability of inferences about the effects of adaptive treatment strategies. In addition, monitoring is a health intervention in itself with costs and benefits, and stakeholders may be interested in the effect of monitoring when adopting adaptive treatment strategies. This paper demonstrates how to exploit nonsystematic covariate monitoring in EHR-based studies to both improve the generalizability of causal inferences and to evaluate the health impact of monitoring when evaluating adaptive treatment strategies. Using a real world, EHR-based, comparative effectiveness research (CER) study of patients with type II diabetes mellitus, we illustrate how the evaluation of joint dynamic treatment and static monitoring interventions can improve CER evidence and describe two alternate estimation approaches based on inverse probability weighting (IPW). First, we demonstrate the poor performance of the standard estimator of the effects of joint treatment-monitoring interventions, due to a large decrease in data support and concerns over finite-sample bias from near-violations of the positivity assumption (PA) for the monitoring process. Second, we detail an alternate IPW estimator using a no direct effect assumption. We demonstrate that this estimator can improve efficiency but at the potential cost of increase in bias from violations of the PA for the treatment process.


Subject(s)
Diabetes Mellitus, Type 2 , Bias , Causality , Diabetes Mellitus, Type 2/drug therapy , Electronic Health Records , Humans , Probability
8.
Clin Infect Dis ; 70(6): 1176-1185, 2020 03 03.
Article in English | MEDLINE | ID: mdl-31044245

ABSTRACT

BACKGROUND: People living with human immunodeficiency virus (HIV; PLWH) have a markedly elevated anal cancer risk, largely due to loss of immunoregulatory control of oncogenic human papillomavirus infection. To better understand anal cancer development and prevention, we determined whether recent, past, cumulative, or nadir/peak CD4+ T-cell count (CD4) and/or HIV-1 RNA level (HIV RNA) best predict anal cancer risk. METHODS: We studied 102 777 PLWH during 1996-2014 from 21 cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. Using demographics-adjusted, cohort-stratified Cox models, we assessed associations between anal cancer risk and various time-updated CD4 and HIV RNA measures, including cumulative and nadir/peak measures during prespecified moving time windows. We compared models using the Akaike information criterion. RESULTS: Cumulative and nadir/peak CD4 or HIV RNA measures from approximately 8.5 to 4.5 years in the past were generally better predictors for anal cancer risk than their corresponding more recent measures. However, the best model included CD4 nadir (ie, the lowest CD4) from approximately 8.5 years to 6 months in the past (hazard ratio [HR] for <50 vs ≥500 cells/µL, 13.4; 95% confidence interval [CI], 3.5-51.0) and proportion of time CD4 <200 cells/µL from approximately 8.5 to 4.5 years in the past (a cumulative measure; HR for 100% vs 0%, 3.1; 95% CI, 1.5-6.6). CONCLUSIONS: Our results are consistent with anal cancer promotion by severe, prolonged HIV-induced immunosuppression. Nadir and cumulative CD4 may represent useful markers for identifying PLWH at higher anal cancer risk.


Subject(s)
Anus Neoplasms , HIV Infections , Anus Neoplasms/epidemiology , CD4 Lymphocyte Count , Canada/epidemiology , HIV , HIV Infections/complications , HIV Infections/epidemiology , Humans , Immunosuppression Therapy , United States/epidemiology , Viral Load , Viremia
9.
Am J Epidemiol ; 189(2): 133-145, 2020 02 28.
Article in English | MEDLINE | ID: mdl-31577030

ABSTRACT

This cohort study sought to estimate the differences in risk of delivering infants who were small or large for gestational age (SGA or LGA, respectively) according to exercise during the first trimester of pregnancy (vs. no exercise) among 2,286 women receiving care at Kaiser Permanente Northern California in 2013-2017. Exercise was assessed by questionnaire. SGA and LGA were determined by the sex- and gestational-age-specific birthweight distributions of the 2017 US Natality file. Risk differences were estimated by targeted maximum likelihood estimation, with and without data-adaptive prediction (machine learning). Analyses were also stratified by prepregnancy weight status. Overall, exercise at the cohort-specific 75th percentile was associated with an increased risk of SGA of 4.5 (95% CI: 2.1, 6.8) per 100 births, and decreased risk of LGA of 2.8 (95% CI: 0.5, 5.1) per 100 births; similar findings were observed among the underweight and normal-weight women, but no associations were found among those with overweight or obesity. Meeting Physical Activity Guidelines was associated with increased risk of SGA and decreased risk of LGA but only among underweight and normal-weight women. Any vigorous exercise reduced the risk of LGA in underweight and normal-weight women only and was not associated with SGA risk.


Subject(s)
Birth Weight , Exercise/physiology , Pregnancy Complications/physiopathology , Pregnancy Trimester, First , Prenatal Care/statistics & numerical data , Adult , Body Weight , California , Female , Gestational Age , Humans , Ideal Body Weight/physiology , Infant, Newborn , Infant, Small for Gestational Age , Likelihood Functions , Longitudinal Studies , Pregnancy , Risk Factors , Thinness/physiopathology
10.
BMC Musculoskelet Disord ; 21(1): 801, 2020 Dec 03.
Article in English | MEDLINE | ID: mdl-33272248

ABSTRACT

BACKGROUND: Bisphosphonate (BP) therapy has been associated with atypical femur fracture (AFF). However, the threshold of treatment duration leading to increased AFF risk is unclear. In a retrospective cohort of older women initiating BP, we compared the AFF risk associated with treatment for at least three years to the risk associated with treatment less than three years. METHODS: We used observational data from a large population of female members of an integrated healthcare system who initiated oral BP during 2002-2014. Women were retrospectively followed for incident AFF confirmed by radiologic adjudication. Demographic data, pharmacologic exposures, comorbidity, bone density, and fracture history were ascertained from electronic health records. Inverse probability weighting was used to estimate risk differences comparing the cumulative incidence (risk) of AFF if women discontinued BP within three years to the cumulative incidence of AFF if women continued BP for three or more years, adjusting for potential time-dependent confounding by the aforementioned factors. RESULTS: Among 87,820 women age 45-84 years who initiated BP (mean age 68.6, median T-score - 2.6, 14% with prior major osteoporotic fracture), 16,180 continued BP for three or more years. Forty-six confirmed AFFs occurred during follow-up in the two groups. AFF-free survival was greater for BP treatment < 3 years compared to treatment ≥3 years (p = 0.004 comparing areas under survival curves). At five years, the risk of AFF was 27 per 100,000 (95% confidence interval, CI: 8-46) if women received BP treatment < 3 years and 120 per 100,000 (95% CI: 56-183) if women received BP treatment ≥3 years (risk difference 93 per 100,000, 95% CI: 30-160). By ten years, the risks were 27 (95% CI: 8-46) and 363 (95% CI: 132-593) per 100,000 for BP treatment < 3 and ≥ 3 years, respectively (risk difference 336 per 100,000, 95% CI: 110-570). CONCLUSIONS: Bisphosphonate treatment for 3 or more years was associated with greater risk of AFF than treatment for less than 3 years. Although AFFs are uncommon among BP-treated women, this increased risk should be considered when counseling women about long-term BP use. Future studies should further characterize the dose-response relationship between BP duration and incident AFF and identify patients at highest risk.


Subject(s)
Bone Density Conservation Agents , Femoral Fractures , Aged , Aged, 80 and over , Bone Density Conservation Agents/adverse effects , Diphosphonates/adverse effects , Female , Femoral Fractures/chemically induced , Femoral Fractures/diagnostic imaging , Femoral Fractures/epidemiology , Femur , Humans , Middle Aged , Retrospective Studies , Risk Factors
11.
J Vasc Surg ; 79(2): 451-452, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38245187
12.
Stat Med ; 38(16): 3073-3090, 2019 07 20.
Article in English | MEDLINE | ID: mdl-31025411

ABSTRACT

Electronic health records (EHR) data provide a cost- and time-effective opportunity to conduct cohort studies of the effects of multiple time-point interventions in the diverse patient population found in real-world clinical settings. Because the computational cost of analyzing EHR data at daily (or more granular) scale can be quite high, a pragmatic approach has been to partition the follow-up into coarser intervals of pre-specified length (eg, quarterly or monthly intervals). The feasibility and practical impact of analyzing EHR data at a granular scale has not been previously evaluated. We start filling these gaps by leveraging large-scale EHR data from a diabetes study to develop a scalable targeted learning approach that allows analyses with small intervals. We then study the practical effects of selecting different coarsening intervals on inferences by reanalyzing data from the same large-scale pool of patients. Specifically, we map daily EHR data into four analytic datasets using 90-, 30-, 15-, and 5-day intervals. We apply a semiparametric and doubly robust estimation approach, the longitudinal Targeted Minimum Loss-Based Estimation (TMLE), to estimate the causal effects of four dynamic treatment rules with each dataset, and compare the resulting inferences. To overcome the computational challenges presented by the size of these data, we propose a novel TMLE implementation, the "long-format TMLE," and rely on the latest advances in scalable data-adaptive machine-learning software, xgboost and h2o, for estimation of the TMLE nuisance parameters.


Subject(s)
Algorithms , Electronic Health Records , Longitudinal Studies , Causality , Computer Simulation , Diabetes Mellitus , Humans , Machine Learning , Reproducibility of Results
13.
J Am Acad Dermatol ; 80(4): 998-1005, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30458208

ABSTRACT

BACKGROUND: The effectiveness of 5-fluorouracil compared with that of imiquimod for preventing keratinocyte carcinoma is unknown. OBJECTIVE: To compare the effectiveness of 5-fluorouracil and that of imiquimod in preventing keratinocyte carcinoma in a real-world practice setting. METHODS: We identified 5700 subjects who filled prescriptions for 5-fluorouracil or imiquimod for treatment of actinic keratosis in 2007. An intention-to-treat analysis controlling for potential confounding variables was used to calculate 2- and 5-year cumulative risk differences for subsequent keratinocyte carcinoma overall and in field-treated areas. RESULTS: 5-Fluorouracil was associated with a statistically significant decreased risk of any keratinocyte carcinoma compared with imiquimod (adjusted hazard ratio [aHR], 0.86; 95% confidence interval [CI], 0.76-0.97), but there were no significant differences in risk by tumor subtype (for squamous cell carcinoma: aHR, 0.89; 95% CI, 0.74-1.07; for basal cell carcinoma: aHR, 0.87; 95% CI, 0.74-1.03) or site-specific keratinocyte carcinoma (aHR, 0.96; 95% CI, 0.81-1.14). There were no significant differences in 2- or 5-year cumulative risk of keratinocyte carcinoma among those treated with 5-fluorouracil versus with imiquimod. LIMITATIONS: Generalizability to other practice settings may be limited. CONCLUSIONS: Whereas 5-fluorouracil was more effective in reducing keratinocyte carcinoma risk overall, we found no differences in the short- or long-term risk of subsequent site-specific keratinocyte carcinoma in a real-world practice setting.


Subject(s)
Carcinoma, Basal Cell/epidemiology , Carcinoma, Squamous Cell/epidemiology , Fluorouracil/therapeutic use , Imiquimod/therapeutic use , Keratosis, Actinic/drug therapy , Skin Neoplasms/epidemiology , Administration, Cutaneous , Aged , California/epidemiology , Carcinoma, Basal Cell/prevention & control , Carcinoma, Squamous Cell/prevention & control , Comparative Effectiveness Research , Female , Fluorouracil/administration & dosage , Humans , Imiquimod/administration & dosage , Intention to Treat Analysis , Keratinocytes/pathology , Longitudinal Studies , Male , Middle Aged , Retrospective Studies , Risk Factors , Skin Neoplasms/prevention & control
14.
J Am Acad Dermatol ; 78(4): 710-716, 2018 04.
Article in English | MEDLINE | ID: mdl-29277731

ABSTRACT

BACKGROUND: The most widely used topical agents for the field-based treatment of multiple actinic keratoses (AKs) are 5-fluorouracil and imiquimod, but their comparative effectiveness has not been assessed in a real-world setting. OBJECTIVE: We compared the effectiveness of 5-fluorouracil and imiquimod in reducing risk for subsequent AKs in a large, integrated health care delivery system in northern California. METHODS: In this cohort study, we identified adult health plan members who had an AK diagnosed in 2007 and who subsequently filled a prescription for 5-fluorouracil or imiquimod (N = 5700). We followed subjects for subsequent AKs identified by the International Classification of Diseases codes and estimated the 2-year (short-term) and 5-year (long-term) differences in cumulative risk while controlling for potential confounding by pretreatment variables. RESULTS: 5-Fluorouracil reduced the short-term incidence of subsequent AKs (cumulative risk difference -4.54% [95% confidence interval, -7.91% to -1.17%]), but there was no statistically significant evidence of a long-term decreased risk (cumulative risk difference -1.43% [95% confidence interval, -3.43% to 0.05%]) compared with that with imiquimod. LIMITATIONS: This is a retrospective study with limited ascertainment of all relevant potential confounding variables. CONCLUSION: We found that 5-fluorouracil appeared to be significantly more effective than imiquimod in the short-term, but not long-term, prevention of subsequent AKs.


Subject(s)
Aminoquinolines/administration & dosage , Fluorouracil/administration & dosage , Keratosis, Actinic/drug therapy , Administration, Topical , Adolescent , Adult , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Imiquimod , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Young Adult
15.
Gynecol Oncol ; 147(1): 11-17, 2017 10.
Article in English | MEDLINE | ID: mdl-28747255

ABSTRACT

OBJECTIVE: To assess recent trends of administering adjuvant gemcitabine-docetaxel (GD) chemotherapy for Stage I uterine leiomyosarcoma, and to compare disease-free and overall survival between women who received and did not receive adjuvant GD chemotherapy. METHODS: All patients diagnosed with Stage I uterine leiomyosarcoma in a California-Colorado population-based health plan inclusive of 2006-2013 were included in a retrospective cohort. Adjuvant GD chemotherapy rates, clinico-pathologic characteristics and survival estimates were assessed. RESULTS: Of 111 women with Stage I uterine leiomyosarcoma, 33 received adjuvant GD (median 4cycles), 77 received no chemotherapy, and 1 patient excluded for non-GD chemotherapy. GD-chemotherapy and no-chemotherapy groups were similar with respect to age, stage (IA/IB), uterine weight, mitotic index, body mass index, and Charlson comorbidity score. Non-Hispanic white women were twice as likely to receive adjuvant chemotherapy as non-white or Hispanic women (37.7 vs. 17.1%, P=0.02). The proportion of women receiving adjuvant GD chemotherapy increased from 6.5% in 2006-2008 to 46.9% in 2009-2013 (P<0.001). There was no significance difference in unadjusted Kaplan-Meyer estimated disease-free (P=0.95) or overall survival (P=0.43) between GD-chemotherapy and no-chemotherapy cohorts. Corresponding adjusted Cox proportional hazard ratios for adjuvant GD chemotherapy compared to no chemotherapy were 1.01 (95% confidence interval [CI] 0.57-1.80, P=0.97) for recurrence and 1.28 (95% CI 0.69-2.36, P-0.48) for mortality. CONCLUSIONS: Use of adjuvant GD chemotherapy for Stage I uterine leiomyosarcoma has increased significantly in the last decade, despite unclear benefit. Compared to no chemotherapy, 4-6cycles of adjuvant GD chemotherapy does not appear to alter survival outcomes.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Leiomyosarcoma/drug therapy , Uterine Neoplasms/drug therapy , Adult , Aged , Chemotherapy, Adjuvant/trends , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Docetaxel , Female , Humans , Leiomyosarcoma/mortality , Leiomyosarcoma/pathology , Middle Aged , Neoplasm Recurrence, Local/epidemiology , Proportional Hazards Models , Retrospective Studies , Taxoids/administration & dosage , Uterine Neoplasms/mortality , Uterine Neoplasms/pathology , Gemcitabine
16.
J Stat Softw ; 812017.
Article in English | MEDLINE | ID: mdl-29104515

ABSTRACT

The simcausal R package is a tool for specification and simulation of complex longitudinal data structures that are based on non-parametric structural equation models. The package aims to provide a flexible tool for simplifying the conduct of transparent and reproducible simulation studies, with a particular emphasis on the types of data and interventions frequently encountered in real-world causal inference problems, such as, observational data with time-dependent confounding, selection bias, and random monitoring processes. The package interface allows for concise expression of complex functional dependencies between a large number of nodes, where each node may represent a measurement at a specific time point. The package allows for specification and simulation of counterfactual data under various user-specified interventions (e.g., static, dynamic, deterministic, or stochastic). In particular, the interventions may represent exposures to treatment regimens, the occurrence or non-occurrence of right-censoring events, or of clinical monitoring events. Finally, the package enables the computation of a selected set of user-specified features of the distribution of the counterfactual data that represent common causal quantities of interest, such as, treatment-specific means, the average treatment effects and coefficients from working marginal structural models. The applicability of simcausal is demonstrated by replicating the results of two published simulation studies.

17.
Clin Trials ; 13(3): 286-93, 2016 06.
Article in English | MEDLINE | ID: mdl-27034455

ABSTRACT

BACKGROUND: Challenges to effective pharmacologic management of symptomatic diabetic peripheral neuropathy include the limited effectiveness of available medicines, frequent side effects, and the need for ongoing symptom assessment and treatment titration for maximal effectiveness. We present here the rationale and implementation challenges of the Diabetes Telephone Study, a randomized trial designed to improve medication treatment, titration, and quality of life among patients with symptomatic diabetic peripheral neuropathy. METHODS: We implemented a pragmatic cluster randomized controlled trial to test the effectiveness of an automated interactive voice response tool designed to provide physicians with real-time patient-reported data about responses to newly prescribed diabetic peripheral neuropathy medicines. A total of 1834 primary care physicians treating patients in the diabetes registry at Kaiser Permanente Northern California were randomized into the intervention or control arm. In September 2014, we began identification and recruitment of patients assigned to physicians in the intervention group who receive three brief interactive calls every 2 months after a medication is prescribed to alleviate diabetic peripheral neuropathy symptoms. These calls provide patients with the opportunity to report on symptoms, side effects, self-titration of medication dose and overall satisfaction with treatment. We plan to compare changes in self-reported quality of life between the intervention group and patients in the control group who receive three non-interactive automated educational phone calls. RESULTS: Successful implementation of this clinical trial required robust stakeholder engagement to help tailor the intervention and to address pragmatic concerns such as provider time constraints. As of 27 October 2015, we had screened 2078 patients, 1447 of whom were eligible for participation. We consented and enrolled 1206 or 83% of those eligible. Among those enrolled, 53% are women and the mean age is 67 (standard deviation = 12) years. The racial ethnic make-up is 56% White, 8% Asian, 13% Black or African American, and 19% Hispanic or Latino. CONCLUSION: Innovative strategies are needed to guide improvements in healthcare delivery for patients with symptomatic diabetic peripheral neuropathy. This trial aims to assess whether real-time collection and clinical feedback of patient treatment experiences can reduce patient symptom burden. Implementation of a clinical trial closely involving clinical care required researchers to partner with clinicians. If successful, this intervention provides a critical information feedback loop that would optimize diabetic peripheral neuropathy medication titration through widely available interactive voice response technology.


Subject(s)
Diabetic Neuropathies/drug therapy , Patient Reported Outcome Measures , Telephone , Aged , Automation , Female , Humans , Male , Middle Aged , Patient Participation , Quality of Life , Treatment Outcome
18.
J Gen Intern Med ; 30(11): 1645-50, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25944019

ABSTRACT

BACKGROUND: Reducing patient cost-sharing and engaging patients in disease management activities have been shown to increase uptake of evidence-based care. OBJECTIVE: To evaluate the effect of employer purchase of a disease-specific plan with reduced cost-sharing and disease management (the Diabetes Health Plan/DHP) on medication adherence among eligible employees and dependents. DESIGN: Employer-level "intent to treat" cohort study, including data from eligible employees and their dependents with diabetes, regardless of whether they were enrolled in the DHP. SETTING: Employers that contracted with a large national health plan administrator in 2009, 2010, and/or 2011. PARTICIPANTS: Ten employers that purchased the DHP and 191 employers that did not (controls). Inverse probability weighting (IPW) estimation was used to adjust for inter-group differences. INTERVENTION: The DHP includes free or low-cost medications and physician visits. Enrollment strategies and specific benefit designs are determined by the employer and vary in practice. DHP participants are notified up front that they must engage in their own health care (e.g., receiving diabetes-related screening) in order to remain enrolled. MAIN OUTCOME MEASURE: Mean employee adherence to metformin, statins, and ACE/ARBs at the employer level at one year post-DHP implementation, as measured by the proportion of days covered (PDC). RESULTS: Baseline adherence to the three medications was similar across DHP and control employers, ranging from 64 to 69 %. In the first year after DHP implementation, predicted employer-level adherence for metformin (+4.9 percentage points, p = 0.017), statins (+4.8, p = 0.019), and ACE/ARBs (+4.4, p = 0.02) was higher with DHP purchase. LIMITATIONS: Non-randomized, observational study. CONCLUSIONS: The Diabetes Health Plan, an innovative health plan that combines reduced cost-sharing and disease management with an up-front requirement of enrollee participation in his or her own health care, is associated with a modest improvement in medication adherence at 12 months.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Health Benefit Plans, Employee/organization & administration , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Medication Adherence/statistics & numerical data , Metformin/therapeutic use , Adult , Aged , Angiotensin Receptor Antagonists/economics , Angiotensin Receptor Antagonists/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/economics , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Cost Sharing/economics , Diabetes Mellitus, Type 2/economics , Disease Management , Drug Costs/statistics & numerical data , Female , Health Benefit Plans, Employee/economics , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/economics , Hypoglycemic Agents/economics , Hypoglycemic Agents/therapeutic use , Imidazoles/economics , Imidazoles/therapeutic use , Male , Metformin/economics , Middle Aged , Rosuvastatin Calcium/economics , Rosuvastatin Calcium/therapeutic use , Tetrazoles/economics , Tetrazoles/therapeutic use , United States
19.
Stat Med ; 34(5): 753-81, 2015 Feb 28.
Article in English | MEDLINE | ID: mdl-25488047

ABSTRACT

The high-dimensional propensity score (hdPS) algorithm was proposed for automation of confounding adjustment in problems involving large healthcare databases. It has been evaluated in comparative effectiveness research (CER) with point treatments to handle baseline confounding through matching or covariance adjustment on the hdPS. In observational studies with time-varying interventions, such hdPS approaches are often inadequate to handle time-dependent confounding and selection bias. Inverse probability weighting (IPW) estimation to fit marginal structural models can adequately handle these biases under the fundamental assumption of no unmeasured confounders. Upholding of this assumption relies on the selection of an adequate set of covariates for bias adjustment. We describe the application and performance of the hdPS algorithm to improve covariate selection in CER with time-varying interventions based on IPW estimation and explore stabilization of the resulting estimates using Super Learning. The evaluation is based on both the analysis of electronic health records data in a real-world CER study of adults with type 2 diabetes and a simulation study. This report (i) establishes the feasibility of IPW estimation with the hdPS algorithm based on large electronic health records databases, (ii) demonstrates little impact on inferences when supplementing the set of expert-selected covariates using the hdPS algorithm in a setting with extensive background knowledge, (iii) supports the application of the hdPS algorithm in discovery settings with little background knowledge or limited data availability, and (iv) motivates the application of Super Learning to stabilize effect estimates based on the hdPS algorithm.


Subject(s)
Algorithms , Comparative Effectiveness Research/statistics & numerical data , Propensity Score , Adult , Biostatistics , Cohort Studies , Computer Simulation , Confounding Factors, Epidemiologic , Databases, Factual/statistics & numerical data , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Electronic Health Records/statistics & numerical data , Female , Humans , Male , Models, Statistical , Multicenter Studies as Topic/statistics & numerical data , Observational Studies as Topic/statistics & numerical data , Probability , Retrospective Studies , Selection Bias
20.
Prev Chronic Dis ; 12: E207, 2015 Nov 25.
Article in English | MEDLINE | ID: mdl-26605707

ABSTRACT

INTRODUCTION: Health coaching can improve lifestyle behaviors known to prevent or manage chronic conditions. Little is known about effective ways to encourage health and wellness coaching among people who might benefit. The purpose of this randomized encouragement trial was to assess the relative success of 3 outreach methods (secured email message, telephone message, and mailed letter) on the use of wellness coaching by people with prediabetes. METHODS: A total of 14,584 Kaiser Permanente Northern California (KPNC) patients with diagnosed prediabetes (fasting plasma glucose, 110-125mg/dL) were randomly assigned to be contacted via 1 of 4 intervention arms from January through May 2013. The uptake rate (making an appointment at the Wellness Coaching Center [WCC]) was assessed, and the association between uptake rate and patient characteristics was examined via multivariable logistic regression. RESULTS: The overall uptake rate across intervention arms was 1.9%. Secured email message had the highest uptake rate (3.0%), followed by letters and telephone messages (P < .05 for all pairwise comparisons). No participants in the usual-care arm (ie, no outreach) made an appointment with the WCC. For each year of increased age, the estimated odds of the uptake increased by 1.02 (odds ratio [OR] = 1.02; 95% CI, 1.01-1.04). Women were nearly twice as likely to make an appointment at the WCC as men (OR = 1.87; 95% CI, 1.40-2.51). CONCLUSION: Our results suggest that the WCC can recruit and encourage KPNC members with prediabetes to participate in the WCC. Future research should focus on increasing participation rates in health coaching among patients who may benefit.


Subject(s)
Electronic Mail , Health Promotion/methods , Mass Media , Prediabetic State/diagnosis , Telephone , Adolescent , Adult , Aged , Aged, 80 and over , California , Diabetes Mellitus, Type 2/prevention & control , Female , Glucose Tolerance Test , Humans , Insurance, Health , Life Style , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Outcome Assessment, Health Care , Young Adult
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