TY - JOUR
T1 - Misidentification of Dementia in Medicare Claims and Related Costs
AU - Zhu, Carolyn W.
AU - Ornstein, Katherine A.
AU - Cosentino, Stephanie
AU - Gu, Yian
AU - Andrews, Howard
AU - Stern, Yaakov
N1 - Publisher Copyright:
© 2018, Copyright the Author Journal compilation © 2018, The American Geriatrics Society
PY - 2019/2
Y1 - 2019/2
N2 - Objectives: To examine how misidentification of dementia affects estimation of Medicare costs in a largely minority cohort of participants for whom accurate in-person diagnoses are available. Design: Prospective cohort study. Setting: Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries aged 65 and older. Participants: Individuals clinically diagnosed with dementia (n=495) and individuals clinically diagnosed without dementia (n=1,701). Measurements: Medicare claims-identified dementia was defined according to the presence of any International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for Alzheimer's disease and related dementias in all available claims during the study period. Participant characteristics associated with claims misidentification of dementia were estimated using logistic regression. Effects of dementia misidentification on Medicare expenditures were estimated using generalized linear models. Results: Medicare claims correctly identified 250 of the 495 (51%) dementia cases and 1,565 of the 1,701 (92%) nondementia cases. Sensitivity of claims-identified dementia was 0.51, and specificity was 0.92. Average annual Medicare expenditures were $14,721 for a beneficiary with a clinical diagnosis of dementia, and $18,208 for a beneficiary with claim-identified dementia, suggesting an overestimation of $3,487 per person per year when Medicare claims were used to identify dementia. Total annual expenditures for all beneficiaries with claims-identified dementia were $258,707 lower than that for all those who were clinically diagnosed, suggesting an overall underestimation of total Medicare expenditures if Medicare claims were used to identify dementia. Different types of misidentification have different effects on dementia-related cost estimates. Average annual expenditures per person were highest for false positives. Conclusion: Misidentification of dementia in Medicare claims is common. Using claims to identify dementia may result in significantly biased estimates of the cost of dementia. J Am Geriatr Soc 67:269–276, 2019.
AB - Objectives: To examine how misidentification of dementia affects estimation of Medicare costs in a largely minority cohort of participants for whom accurate in-person diagnoses are available. Design: Prospective cohort study. Setting: Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries aged 65 and older. Participants: Individuals clinically diagnosed with dementia (n=495) and individuals clinically diagnosed without dementia (n=1,701). Measurements: Medicare claims-identified dementia was defined according to the presence of any International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for Alzheimer's disease and related dementias in all available claims during the study period. Participant characteristics associated with claims misidentification of dementia were estimated using logistic regression. Effects of dementia misidentification on Medicare expenditures were estimated using generalized linear models. Results: Medicare claims correctly identified 250 of the 495 (51%) dementia cases and 1,565 of the 1,701 (92%) nondementia cases. Sensitivity of claims-identified dementia was 0.51, and specificity was 0.92. Average annual Medicare expenditures were $14,721 for a beneficiary with a clinical diagnosis of dementia, and $18,208 for a beneficiary with claim-identified dementia, suggesting an overestimation of $3,487 per person per year when Medicare claims were used to identify dementia. Total annual expenditures for all beneficiaries with claims-identified dementia were $258,707 lower than that for all those who were clinically diagnosed, suggesting an overall underestimation of total Medicare expenditures if Medicare claims were used to identify dementia. Different types of misidentification have different effects on dementia-related cost estimates. Average annual expenditures per person were highest for false positives. Conclusion: Misidentification of dementia in Medicare claims is common. Using claims to identify dementia may result in significantly biased estimates of the cost of dementia. J Am Geriatr Soc 67:269–276, 2019.
KW - Medicare claims
KW - clinical diagnosis
KW - cost
KW - dementia
UR - http://www.scopus.com/inward/record.url?scp=85054901427&partnerID=8YFLogxK
U2 - 10.1111/jgs.15638
DO - 10.1111/jgs.15638
M3 - Article
C2 - 30315744
AN - SCOPUS:85054901427
SN - 0002-8614
VL - 67
SP - 269
EP - 276
JO - Journal of the American Geriatrics Society
JF - Journal of the American Geriatrics Society
IS - 2
ER -