Person:

Newhouse, Joseph

BACKGROUND/OBJECTIVES: No data exist regarding the validity of International Classification of Disease (ICD)-10 dementia diagnoses within Medicare claims data. We examined the accuracy of claims-based diagnoses with respect to expert clinician adjudication using a novel database with individual-level linkages between electronic health record (EHR) and claims. DESIGN: In this retrospective observational study, two neurologists and two psychiatrists performed a standardized review of patients’ medical records from January-2016 to December-2018, and adjudicated dementia status. We measured the accuracy of three claims-based definitions of dementia against the reference standard. SETTING: Mass-General-Brigham Healthcare (MGB), Massachusetts, USA. PARTICIPANTS: From an eligible population of 40,690 fee-for-service (FFS) Medicare beneficiaries, aged 65-years and older, within the MGB Accountable Care Organization (ACO), we generated a random sample of 1,002 patients, stratified by the pretest likelihood of dementia using administrative surrogates. INTERVENTION: None. MEASUREMENTS: We evaluated the accuracy (area-under-receiver-operating-curve [AUROC]) and calibration (calibration-in-the-large [CITL] and calibration slope) of three ICD-10 claims-based definitions of dementia against clinician-adjudicated standards. We applied inverse probability weighting to reconstruct the eligible population and reported the mean and 95% confidence interval (95% CI) for all performance characteristics, using 10-fold cross-validation (CV). RESULTS: Beneficiaries had an average age of 75.3-years and were predominately female (59%) and non-Hispanic white (93%). The adjudicated prevalence of dementia in the eligible population was 7%. The best performing definition demonstrated excellent accuracy (CV-AUC 0.94; 95% CI 0.92-0.96) and was well-calibrated to the reference standard of clinician-adjudicated dementia (CV-CITL <0.001, CV-slope 0.97). CONCLUSION: This study is the first to validate ICD-10 diagnostic codes against a robust and replicable approach to dementia ascertainment using a real-world clinical reference standard. The best performing definition includes diagnostic codes with strong face validity and outperforms an updated version of a previously validated ICD-9 definition of dementia.

Importance. Federally qualified health centers (FQHCs) receive federal funding to serve medically underserved areas and provide a range of services including comprehensive primary care, enabling services, and behavioral health care. Greater funding for FQHCs could increase the local availability of clinic-based care and help reduce more costly resource use, such as emergency department visits (ED). Objective. To examine the impact of funding increases for FQHCs after the ACA on the use of FQHCs and EDs. Methods. Retrospective study using the Massachusetts All Payer Claims Database (APCD) 2010-2013 that included APCD enrollees in 559 Massachusetts ZIP codes (N=6,173,563 in 2010). We calculated shift-share predictions of changes in FQHC funding at the ZIP code-level for FQHCs that received Community Health Center funds in any year, 2010-13 (N=31). Outcomes were the number of ZIP code enrollees with visits to FQHCs and EDs, overall and for emergent and non-emergent diagnoses. Results. In 2010, 4% of study subjects visited a FQHC, and they were more likely to be younger, have Medicaid, and live in low-income areas. We found that a standard deviation increase in prior year FQHC funding (+31 percentage point (pp)) at the ZIP code level was associated with a 2.3pp (95% CI 0.7pp to 3.8pp) increase in enrollees with FQHC visits and a 1.3pp (95% CI -2.3pp to -0.3pp) decrease in enrollees with non-emergent ED visits, but no significant change in emergent ED visits (0.3pp, 95% CI -0.8pp to 1.4pp). Conclusions. We found that areas exposed to greater FQHC funding increases had more growth in the number of enrollees seen by FQHCs and greater reductions in ED visits for non-emergent conditions. Investment in FQHCs could be a promising approach to increase access to care for underserved populations and reduce costly ED visits, especially for primary care treatable or non-emergent conditions.

IMPORTANCE The Patient Protection and Affordable Care Act (ACA) temporarily increased primary care practitioners’ (PCP) Medicaid fees to that of Medicare for 2013 to 2014 (fee bump) to help accommodate potential increases in demand for care with ACA coverage expansion. This also increased fees for PCPs treating dual-eligible Medicare and Medicaid beneficiaries in many states and eliminated payment differentials for dual-eligible vs non–dual-eligible Medicare beneficiaries that could limit access to care. OBJECTIVE To examine the association between the ACA fee bump and primary care visits for dual eligible Medicare and Medicaid beneficiaries. DESIGN, SETTING, AND PARTICIPANTS This cohort study used a difference-in-difference design and Medicare claims data from 2012 to 2016 to compare changes in visit rates for full-subsidy dual eligible Medicare and Medicaid beneficiaries vs non–dual-eligible Medicare beneficiaries with low income whose fees did not change. Changes were examined overall and separately in states with temporary, extended, or minimal fee increases for dual-eligible vs non–dual-eligible beneficiaries in 2013 to 2014 (mandatory bump) and 2015 to 2016 (postbump or bump extension) vs 2012 (prebump). The study used linear regression models with beneficiary fixed effects, adjusting for time-changing area and beneficiary characteristics. Statistical analysis was performed from February 2018 to November 2019. EXPOSURE ACA-mandated Medicaid fee bump. MAIN OUTCOMES AND MEASURES Primary care visits per 100 beneficiaries overall and visits billed by physicians vs nurse practitioners and physician assistants. RESULTS The study included 3 052 044 dual-eligible and non–dual-eligible beneficiaries in 2012; 1 516 534 (49.7%) were aged 65 years or younger, 1 797 556 (58.9%) were women, and 1 754 626 (57.5%) had non-Hispanic White race/ethnicity. Overall primary care visit rates for dual-eligible beneficiaries were unchanged or decreased slightly relative to non–dual-eligible beneficiaries during the fee bump (2013-2014) and the postbump or bump extension period (2015-2016) vs baseline. Compared with non–dual-eligible beneficiaries, visit rates with primary care physicians declined more uniformly for dual-eligible beneficiaries across state groups and time periods (difference-in-difference: −0.37 [95%CI, −0.43 to −0.32] visits per 100 beneficiaries in 2013-2014 vs 2012; P < .001; and difference-in-difference: −0.62 [95%CI, −0.68 to −0.56] visits per 100 beneficiaries in 2015-2016 vs 2012; P < .001), whereas visits with nurse practitioners and physician assistants increased over time (difference-in-difference: 0.11 [95%CI, 0.08 to 0.14] visits per 100 beneficiaries in 2013-2014 vs 2012; P < .001; and difference-in-difference: 0.46 [95%CI, 0.43 to 0.50] visits per 100 beneficiaries in 2015-2016 vs 2012; P < .001). These changes, however, were not associated with the timing of the payment changes. CONCLUSIONS AND RELEVANCE The ACA fee bump was not associated with increases in primary care visits for dual-eligible Medicare and Medicaid beneficiaries. Visits for dual-eligible beneficiaries with primary care physicians decreased after the ACA, a decrease that was partially offset by increases in visits with nonphysician clinicians.