The Influence of Relational Climate on Health Care Costs A Treatment-Effects Approach Marina Soley-Bori, PhD www.rti.org 1 RTI International is a registered trademark and a trade name of Research Triangle Institute.
Introduction: Diabetes care Social worker Does team Nutritionist Pharmacist functioning influence costs of diabetes care? Psychologist Registered Licensed nurse nurse Primary care provider -Complex to manage (5 comorbidities on average) -Low guideline compliance -Twice the costs of non-diabetic patients Beasley et al. 2004, American Diabetes Association 2008, U.S. Department of Veterans Affairs,2014 , Bojadzievski &Gabbay 2011. 2
Introduction: Relational Climate Shared perceptions of interpersonal interactions including teamwork, conflict resolution, and diversity acceptance Measurement: VA All-Employees Survey (AES) -A spirit of cooperation and teamwork exists in my group -Disputes or conflicts are resolved fairly in my work group - Differences among individuals are respected and valued in my work group Relational climate is associated with better quality of diabetes care, but what about costs? Schneider, Benjamin et al. 2010, Mossholder, Richardson and Settoon 2011, J. K. Benzer et al. 2011, Wagner 2000 3
Study Goal To assess the influence of relational climate on health care costs incurred by diabetic patients, accounting for the endogeneity in quality of care 4
Methods: Data sources and study sample Setting: Veterans Health Administration Data sources: VA administrative datasets and the All Employees Survey Retrospective longitudinal study (2008- 2012) Inclusion criteria: At least 2 diabetes diagnoses (ICD-9 250 250.93) each year between 2008-2012 Assignment of patients to the clinic visited most often based on primary care visits 5
Methods: Costs incurred by diabetic patients Costs incurred by diabetic Cost models adjusted for: patients: • Patient characteristics: Age, gender, marital status, • VA Managerial Cost Accounting national access priority status data abstract Elixhauser index, Nosos risk • Differentiated among outpatient, score, insulin, mental health inpatient and total costs diagnosis Quality of diabetes care (all-or- • Adjusted for inflation: Producer Price none process indicator) Index for General Medical and Surgical Hospitals (Bureau of Labor Statistics) • Clinic characteristics: Relational climate, urban/rural • Adjusted of regional labor cost • Parent facility characteristics: differences: CMS Medicare wage index adjusted for VA market areas (Wagner, Teaching status 2015) 6
Methods: Modeling strategy (I) 1. Longitudinal data (unbalanced panel): Random vs. Evolution of Median Total Costs fixed effects? $8,637 $9,000 $7,803 Hausman test: Ho: Error not correlated with $8,000 $7,212 $6,877 $6,786 regressors (RE preferred model) $7,000 p<.001 clinic and year FE $6,000 $5,000 2008 2009 2010 2011 2012 2. Clustering of individuals assigned to the same clinic Correction in standard errors (robust covariance estimator) 3. Skewed distribution of costs Data cleaning: top-coding, deletion of implausible values and absolute studentized residual above 3.5 Generalized Linear Model (GLM) with the Gamma distribution and the Log link 4. Endogeneity of quality of diabetes care Treatment-effects model 7
Methods: Modeling strategy (II) Costs incurred by Relational Climate diabetic patients Three treatment-effects models with inverse probability weighting regression adjustment estimator Main equation: Cost model (GLM Gamma distribution and log link) Treatment equation: All-or-none model (logistic regression) Assumptions: Conditional independence assumption o Standardized differences, density plots, assessment of the evolution of the study variables across time by treatment group Sufficient overlap assumption o Probability distribution of guideline compliance among compliant and non-compliant individuals Double-robust property o C-statistics, Hosmer-Lemeshow Test 8
Results: Descriptive Statistics (I) Study sample : 1,568,180 patient observations across the study period. In a typical year, 200 clinics, 100 parent facilities and 300,000 patients 65.5 (11.2) Age (years) 96.4% (96.4-96.5) Male Marital Status • Married 35.5% (35.4-35.7) Elixhauser Index 80.7% (80.5-80.8) • 2-4 (both included) Mental Health Diagnosis • Yes 37.9% (37.8-38.1) Insulin • Yes 59.1% (58.9-59.3) 2010 data. N= 327,805 Notes: Mean for continuous variables (SD); percentage for categorical variables (95% CI) 9
Results: Descriptive Statistics (II) Evolution of Total Costs (median) $8,637 $9,000 $7,803 $8,000 $7,212 $6,877 $6,786 $7,000 Evolution of the All-or-None Indicator (% Yes) $6,000 58 56.8 56.5 55.9 $5,000 55.5 56 2008 2009 2010 2011 2012 54 51.6 Evolution of Relational climate (average) 52 12.0 50 11.7 48 11.5 11.5 2008 2009 2010 2011 2012 11.2 11.0 10.9 10.8 10.5 10.0 2008 2009 2010 2011 2012 10
Results: The influence of relational climate on costs 2012 Cost change MR (95% CI) per patient of 1 additional RC unit Cost item 0.995*** Outpatient Q=1 (0.994,0.997) -$64.93 Q=0 non-significant cost-neutral 0.986*** Q=1 (0.982,0.991) -$569.16 Inpatient 0.983*** Q=0 (0.979,0.986) -$468.72 0.989*** Q=1 (0.987,0.991) -$109.95 Total costs 0.993*** Q=0 (0.991,0.995) -$67.97 Notes: MR=Mean Ratio, Q=Quality of diabetes care (measured by the all-or-none process indicator), Q=1 means guideline compliant, Q=0 means non guideline compliant. Cost models also adjusted for age, gender, marital status, enrollment priority, nosos risk scores, mental health diagnosis, insulin, rural/urban, the wage index, and teaching status. 11
Conclusions: Limitations 1. Costs incurred by diabetic patients vs. diabetes-related costs 2. Did not account for Medicare services used by dually eligible veterans 3. Partial modeling of the selection of patients into testing 4. Did not account for the cost of increasing relational climate by one unit 5. VHA population specific results 12
Conclusions/Discussion 1. Relational climate contributes to lower outpatient costs (only among compliant individuals), lower inpatient costs, and lower total costs. The magnitude of the effect is modest though. 2. Future work should measure relational climate in other settings other than primary care (e.g. emergency room) and assess how it influences patient outcomes 3. More than 50% of the clinics had a relational climate score lower than 11.2 (max=15) How do we change relational climate ? • Implementation of the Civility, Respect, and Engagement in the Workforce (CREW) intervention at the VHA 13
More information Questions? Marina Soley-Bori, PhD Research Economist RTI International msoleybori@rti.org 14
Assumptions of the treatment-effects model Assumptions: Standardized differences Conditional independence (lower than 0.1) and variance assumption (balance in the model ratios (closer to 1) covariates) Sufficient overlap assumption Double-robust property (specification of the treatment equation) • C statistic= 0.69 C statistic, Hosmer-Lemeshow • 86% p-values of H-L >0.05 test (with bootstrapping). • 88% p-values of P-L >0.05 Prebigon link test (with bootstrapping)
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