What is the effect of area size when using local area practice style as an instrument?

Brooks, John M.; Tang, Yuexin; Chapman, Cole G.; Cook, Elizabeth; Chrischilles, Elizabeth A.

doi:10.1016/j.jclinepi.2013.04.008

Cited by 15 publications

(23 citation statements)

References 77 publications

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“…As such, ATRs provide an adjusted measure of a local area’s “adjuvant treatment signature.” The ATR method has been used successfully in previous studies of geographic treatment variation and comparative effectiveness, along with methodological papers aimed at better understanding estimates of treatment effectiveness from observational studies with unmeasured confounding [41–47]. A summary of the method is outlined below.…”

Section: Methodsmentioning

confidence: 99%

Geographic variation in the use of adjuvant therapy among elderly patients with resected non-small cell lung cancer

et al. 2016

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Objectives The purpose of this study was to assess to what extent geographic variation in adjuvant treatment for non-small cell lung cancer (NSCLC) patients would remain, after controlling for patient and area-level characteristics. Materials and Methods A retrospective cohort of 18,410 Medicare beneficiaries with resected, stage I-IIIA NSCLC was identified from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Adjuvant therapies were classified as adjuvant chemotherapy (ACT), postoperative radiation therapy (PORT), or no adjuvant therapy. Predicted treatment probabilities were estimated for each patient given their clinical, demographic, and area-level characteristics with multivariate logistic regression. Area Treatment Ratios were used to estimate the propensity of patients in a local area to receive an adjuvant treatment, controlling for characteristics of patients in the area. Areas were categorized as low-, mid- and high-use and mapped for two representative SEER registries. Results Overall, 10%, 12%, and 78% of patients received ACT, PORT and no adjuvant therapy, respectively. Age, sex, stage, type and year of surgery, and comorbidity were associated with adjuvant treatment use. Even after adjusting for patient characteristics, substantial geographic treatment variation remained. High- and low-use areas were tightly juxtaposed within and across SEER registries, often within the same county. In some local areas, patients were up to eight times more likely to receive adjuvant therapy than expected, given their characteristics. On the other hand, almost a quarter of patients lived in local areas in which patients were more than three times less likely to receive ACT than would be predicted. Conclusion Controlling for patient and area-level covariates did not remove geographic variation in adjuvant therapies for resected NSCLC patients. A greater proportion of patients were treated less than expected, rather than more than expected. Further research is needed to better understand its causes and potential impact on outcomes.

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Section: Methodsmentioning

confidence: 99%

Geographic variation in the use of adjuvant therapy among elderly patients with resected non-small cell lung cancer

et al. 2016

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“…This is consistent with previous research assessing the effect of area size when using local area practice style as an instrument. 223 Brooks et al showed that using larger local areas to measure practice styles generate less treatment variation (larger Chow-F values) with larger standard errors of treatment estimates. 223 Brooks et al also suggested that use of larger area sizes may mitigate the bias that local area practice style might be related to ecological factors within smaller areas (e.g.…”

Section: Area Diagnosis Ratios As Instrumentsmentioning

confidence: 99%

“…neighborhood cultural and behavioral factors). 223 However, it is been argued that physician practice styles around individual ZIP codes might have little in common in too large local areas. 96 Therefore, we tested the robustness of our IV models based on instruments of local depression diagnosing styles across different sizes with the minimum number of patients varying from 50 to 200 persons around each ZIP code (Appendix 1-39).…”

Section: Area Diagnosis Ratios As Instrumentsmentioning

confidence: 99%

Investigating effects of diagnosing depression among patients with acute myocardial infarction

Tang¹

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___________________________________George Wehby ii ACKNOWLEDGMENTS I finally made it through graduate school with laughs, tears, and appreciation. Many people have supported and encouraged me during this challenging, but fruitful time in my life. My parents, Ruying Tang and Xiumei Wang have supported me since I was born. Their unconditional love and guidance were invaluable to me. Moving from my hometown Beijing to Iowa City for graduate school was not easy for any of us and it has taken me further away from them, but I love them so much and feel their love every second in my life. I spent my first five years with grandparents, Xueyao Tang and Shufen Yang, who taught me how to be a good person and never give up big dreams when I was a kid. Grandpa passed away when I was in graduate school. I hope that in heaven, he could know that I learned a lot from him and how much I miss him. I also want to specially thank my boyfriend, Brandon Patterson, who has given me constant support in the past few years. He is a smart, passionate, and loving man. Without him, I do not know how I could survive graduate school. I am looking forward to our future. I would like to express my special appreciation and thanks to my advisor John Brooks throughout my graduate school. He has been a tremendous mentor to encourage my research and to allow me to grow as an independent scientist. He taught me what passion is from an enthusiastic and dedicated researcher. John has everything a graduate student needs from an advisor. My special thanks also go to Bill Doucette, Jill Kauer, Mary Schroeder, and George Wehby who have served as my committee members and provided constant support and advice on my dissertation and career development. I also want to extend my deep gratitude to many other faculties, , who have helped me during my graduate school. iii I want to thank many other colleagues at the College of Pharmacy for shaping my experiences in the past five years: . A special thank you to Tamara Wilde, Beth Cook, and Lois Baker for helping me through big and small things in my graduate school. My friends in the United States have also made my life so much easier and cheerful in Iowa City. Especially, Min Wang started graduate school the same year as me. We have been through a lot of laughs and complain in our girl's chat that helps with our mental health significantly in graduate school, while being so far away from family. Mariah Gerali, Earldean and Bill Miller have also made me feel home and family and turned my life in graduate school wonderful.iv ABSTRACT Observational data and alternative estimators with correct interpretations have been used to assess the "right" treatment rates in previous studies. However, no systematic analytical approach has been proposed to examine whether the existing diagnosis rates were right in practice. This study used patients with acute myocardial infarction (AMI) as an example to demonstrate use of observational data to explore the clinical and economic effects of depression diagnosis and the "right" depress...

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“…Observed geographic variation in rates of ACE/ARB treatment suggests that prescribing of ACE/ARBs may be sensitive to the beliefs, preferences, or practice styles of physicians across areas. [85][86][87] This geographic variation forms the foundation for our instrumental variables analysis. A theoretical model for the factors likely to be affecting decision to use ACE/ARBs, the effectiveness of ACE/ARBs, and survival for patients with AMI is described below.…”

Section: Empirical Applicationmentioning

confidence: 99%

“…88 94 Following the findings of previous work exploring the validity of ATRs as instruments in this clinical setting, instrumental variables will be defined in this study using a threshold of 150 patients to create local areas. 87 Area treatment ratios (ATRs) will be calculated for each zip codedefined local area as the ratio of the number of patients observed to have received an ACE/ARB after AMI over the sum of the estimated probabilities of these patients receiving an ACE/ARB after AMI. Predicted ACE/ARB probabilities will be generated using a multivariate logistic model of ACE/ARB receipt across all patients in the analytical sample.…”

Section: Theoretical Modelmentioning

confidence: 99%

Identification of population average treatment effects using nonlinear instrumental variables estimators

Chapman¹

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What is the effect of area size when using local area practice style as an instrument?

Cited by 15 publications

References 77 publications

Geographic variation in the use of adjuvant therapy among elderly patients with resected non-small cell lung cancer

Geographic variation in the use of adjuvant therapy among elderly patients with resected non-small cell lung cancer

Investigating effects of diagnosing depression among patients with acute myocardial infarction

Identification of population average treatment effects using nonlinear instrumental variables estimators

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