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Research With Medicare Claim Data. Xinhua Yu, MD PhD Division of Epidemiology and Biostatistics School of Public Health University of Memphis June 22, 2012. Outlines. Medicare program overview Bill process and claim data Data structure and important variables
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Research With Medicare Claim Data Xinhua Yu, MD PhD Division of Epidemiology and Biostatistics School of Public Health University of Memphis June 22, 2012
Outlines • Medicare program overview • Bill process and claim data • Data structure and important variables • Requesting CMS Medicare data • Data analysis • Research applications • Discussion
Medicare Program • National health insurance for age >=65, or people with certain disabilities, or people with ESRD etc. • 1965 - Title XVIII of the Social Security Act • 7/1/1966 - Medicare Program started • 2003, Medicare Prescription Drug, Improvement, and Modernization Act (MMA) • 2006 prescription drug program (Part D) started
Medicare Coverage (Entitlement) • Part A , or Hospital Insurance (HI) • Part B, or Supplemental Medical Insurance (SMI) • Part “C”, or Medicare Advantage Plans (HMO, PPO) • Part D, or Prescription Drug Coverage
Medicare Part A Benefits • Hospital care • Skilled nursing facility (SNF) care • Home health care • skilled nursing and rehabilitation care • patient confined to home • Hospice care (added in 1983) • For terminally ill patients with a life expectancy of 6 months or less
Part A Eligibility • Elderly • Person is eligible if they or their spouse worked 40, or more, quarters in their lifetime and paid Medicare tax while working • For those who did not work 40 quarters, enrollment is possible by paying a monthly premium • Disabled • a person who has received Social Security disability benefits for 24 months • ESRD- persons with end-stage renal disease, ALS - persons with Amyotrophic Lateral Sclerosis (ALS), or Lou Gehrig’s Disease
Part B Benefits • Physician services (including nurse practitioners, physician assistants etc), and services provided by other providers (e.g., health departments) • Facility charges for hospital outpatient services and ambulatory care centers • Note: a person who is seen in a hospital or hospital outpatient setting will generally generate two claims, one from the facility and one from the physician • Durable Medical Equipment • Must pay a premium to be enrolled in part B
Medicare Funding and Payment • Part A: Medicare Hospital Insurance Trust Fund (Medicare tax) • 98% people >=65 are enrolled in part A • Part B and D: Supplementary Medicare Insurance Fund (beneficiary premium and congress appropriation) • 96% elderly part A beneficiaries are enrolled in part B • ~60% elderly enrolled in Part D • Deductable and coinsurance
Types of Medicare Program • Fee-for-service (FFS) or traditional Medicare program • Medicare managed care (now Medicare Advantage plan, Part C) began in 1985 • Risk based: insurance co. receive a capitated money, and plan assumes financial risk • Cost based • 12-16% of beneficiaries are in managed care • Higher in west coast (CA, OR etc.) • Medicare claims are likely incomplete for these managed care enrollees, thus often excluded in the analysis
Bill and Claims • Claims are bills for services given to the Medicare enrollees • Claims are processed sequentially and through hierarchical system • Help understand the contents of Medicare data and validity of data fields
Type of Services • Institutional • Hospital Inpatient • Hospital Outpatient • Skilled Nursing Care • Home Health Care • Hospice • Non-Institutional • Physician, Laboratory and Other Supplier Services • Durable Medical Equipment
Treatment Medicare Beneficiary Institutional Provider Non-institution Provider Payment/ Denial Claim CWF Host Claim (daily) • Update entitlement data • Check claims for entitlement, deductible, remaining benefit, and duplicates • Authorize full payment, partial payment, denial, or request additional data • Medicare Administrative • Contractor (MAC) • Fiscal Intermediary • Carrier Response • Enter claim into system • Perform consistency and utilization edits • Calculate payment • Deny claims based on • Medicare policy • Return denied claims • to provider Entitlement data (Daily) Claims data (Weekly) CMS • Update EDB with entitlement data • Add claims to National Claims • History Repository (NCHR)
Claim Forms • Uniform bill: UB-92/UB-04, for institutional providers (e.g., hospitals, Skilled Nurse Facilities, home health, hospice) • Facility (institutional) claims • Used to be processed through Fiscal Intermediaries • CMS-1500 form: for non-institutional providers (e.g., physicians, lab, ambulance services, medical equipment bills) • Non-institutional claims • Used to be processed through Carriers • 23 Medicare Administrative Contractors (MACs) process both bills • 15 MACs for part A and B, 4 MACs for DME, and 4 for Home health and hospice • Components are different between these two forms
Research Claim Files • SAF: Standard Analytical Files, i.e., claim based files • Contain “final action” claims • Inpatient, outpatient, physician services etc. • MedPAR: Medicare Provider Analysis and Review • Each observation contains aggregated data of all facility claims related to one episode of care • An episode of care is either a hospital or skilled nursing facility stay.
SAFs and MedPAR • Each SAF contains “final action” claims • All adjustment (partial pay, denial, amendment) are rolled up into one record • SAF is available for each type of services • For inpatient services • SAF is more detailed (e.g., attending physician ID) • But MedPAR is easier to work with • 99% of inpatient SAF contain only one record for each hospital stay, thus essentially the same as MedPAR • Requesting SAF costs more than requesting MedPAR
Example: Emergency Room Visit • ER services are considered outpatient services • But ER is usually attached to a hospital • Billed using facility forms (UB-92/04) • Outpatient SAF • What if ER results in a hospital admission? • Becomes Part A (hospitalization services) • Inpatient SAF/ MedPAR • Physician services are Part B • Carrier files will have them • So you need all files to capture diagnosis, procedures, and discharge destination for an ER visit
3. Medicare Data Structure http://www.ccwdata.org/data-dictionaries/index.htm
Beneficiary Summary File (Denominator File) • A calendar year file (cross-sectional file) • All eligible Medicare beneficiaries who ever enrolled (>= 1day) in Medicare • Limited by the criteria you requested • Served as the denominator for calculating rate or prevalence • Contains basic demographic, coverage, HMO, and part D enrollment information (discussed later)
Demographic Variables • Encrypted beneficiary ID • Encrypted from HIC (11 digit unique identifier that is related to SSN) • Can be linked with multiple claim files • Date of birth (age) • There are disabled people with age <65 • Sex • Race • Sources: social security administration (SSA), railroad board (RRB)
Age • It is better to calculate the age variable by yourself based on date of birth • The age variable in the file is calculated as of Dec. 31 in the previous year, thus misclassify those turning 65 during the study year as 64 • Something wrong with really really old people • Medicare had higher percent of people with >100 than the census • There are people with age >120 which is still very unlikely • i.e., some deaths are missed • Could be excluded in the analysis (a very small population)
Race/ethnicity • Since 1994, race codes were: white, black, Asian, Hispanic, Native American, other, unknown • The sensitivity for the Hispanics code is estimated about 35%, i.e., only one third of Hispanics recorded themselves as Hispanics • But specificity is very high, i.e., if they claim themselves Hispanics, they are almost sure Hispanics • Many people claim themselves as other • No penalty for doing that • Research Triangle Institute Race variable • Higher sensitivity (60%+) for identifying Hispanic population
Sex • Sex is coded 1=male 2=female • There are no missing values for this field • Persons with missing information have it filled according to the rule: if age is less than 65 and sex missing then sex=male if age is greater than or equal to 65 and sex is missing then sex=female • Thus there are “female” people with prostate disease
Mortality • Date of death • Date of death validation indicator (“V”) • If date of death is not empty, beneficiary is died • 100% deaths are validated • But about 96% of death dates are validated • Survival time may be over-estimated if unvalidated date of death is recorded as end of month • Source is from SSA and claim info (e.g. hospital discharge status is dead)
Medicare Enrollment Status • Medicare Status Code (MSC) combines current entitlement and ESRD • 10= Aged w/out ESRD • 11= Aged w/ ESRD • 20= Disabled w/out ESRD • 21= Disabled w/ ESRD • 31= ESRD only • Often we excluded those with ESRD as they have different health care utilization patterns • Disabled with age <65 are often excluded as well • Many of them are in Medicaid as well
State Buy-in • Medicaid paying Medicare premiums • All states exercise the option of paying Medicare premiums for at least some people • This can take 3 forms: • State pays premiums only (5%) • State pays premiums and cost sharing (45%) • State provides full Medicaid benefits (50%) • Monthly indicator (buy-in part A, B, or both) • Those with state buy-in can e assumed to have lower income
Benefit Coverage/Enrollment Indicator • Monthly entitlement/buy-in indicator • Not entitled (0) • Part A only (1) • Part B only (2) • Part A and Part B (3) • Part A, State buy-in (A) • Part B, State buy-in (B) • Parts A and B, State buy-in (C) • Also summary month counts for part A,B and buyin • 94% have both Part A and Part B • Often we limited the study to this population • Part A is entitled, while part B is not required
Examples: bene_mdcr_entlmt_buyin_ind • CCCCCCCCCCCC (12 months, A&B SBI) • 333333333333 (12 months A&B) • 111111333333 (5 mon. A, then 7 mon A&B) • 111111111111 (12 months A) • 333300000000 (4 mon A&B,8 mon not elig) • 000000000033 (10 mon not elig,2 mon A&B) • 333333330000 (8 mon A&B, 4 mon not elig)
HMO indicator • Monthly HMO enrollment indicator • Those in the HMO often have incomplete claim history • Claims are not required to be submitted to CMS or not released from CMS • a summary count of Months HMO coverage • No information on the actual managed care types and plans • 12-16% of HMO enrollment
Examples of Monthly HMO Indicators • 000000000000 (never in MCO) • 111111111111 (12 months non-lock-in) • 00000CC00000 (months 6 & 7 in risk MCO) • CCCCCCCCCCCC (12 months in risk MCO) • 00000CCCCCCC (months 6-12 in risk MCO)
Dual Eligible Status • Eligible for both Medicare and Medicaid • Medicaid is means based: i.e., primary for people with income lower than some standard, or needs based • Some dual eligible are in HMO or managed care • Dual eligible variable is better to identify low income patients than state buyin • Dual eligible variable identify more low income patients
Beneficiary Residency • Available in Research Identifiable file (RIF) • State, county and ZIP code of residence are the mailing address for official correspondence • From SSA data • Some persons have their mail sent to another person (e.g., son, daughter, guardian) • Analyses comparing state of treatment with state of residency generally show high concordance • Always use denominator residence information • Residence info on other claims is not validated
Type of Claims • Institutional (facility) claims: UB-92 /UB-04 forms • Inpatient • Outpatient • Skilled nursing facility • Home health agency • Hospice • Non-institutional claims: CMS 1500 form • Physician (and other providers) services • Lab tests and diagnostic exams • Durable medical equipment (DME) • Standard alone ambulatory services
UB 92 /UB-04 Form • Patient demographics • Provider (hospital) ID and location (zip) • Admission/discharge date • Disease diagnosis and procedure: ICD-9 codes • Detailed services (revenue centers in SAF) • Payment and coinsurance • Discharge destination
Hospitalization/MedPAR • Medicare Provider Analysis and Review • Short-stay/Long stay hospitals • Short stay 85% • Long stay hospital 2% • Skilled Nursing Facility (SNF) 13% • Reimbursement for SNF is different (per diem based) • One record per hospital stay in MedPAR • One stay may consist of several records in Inpatient SAF, but these are small proportion • Categorized payment info in MedPAR • Original revenue center codes in SAF
Finding Provider (Hospitals) • Organization NPI • Intelligence free identifier • HIPPA compliant • PRVDR_NUM variable • 6 columns: SSA state (2)+type of facility(4) • Traditional acute care hospitals: 0001-0879 • critical access hospitals: 1300-1399 • Critical access hospitals may not use PPS • Short stay hosp, long stay hosp, and skilled nursing facility (SS_LS_SNF_IND_CD) • Need to separate them in analysis
Length of Stay/Admission and Discharge Dates • LOS=discharge date – admission date • Plus one if the same day hospitalization • LOS for SNF is different • SNF is paid as per diem based on resource utilization groups (RUGs) and has limit in days of stay
Diagnosis, Procedures and DRGs • Clinical information available in four sources: • Medicare Severity Diagnosis Related Group (MS-DRG) (1 per stay, per record) • ICD-9 diagnoses (up to 10 codes: 1 primary, 8 secondary, 1 injury code) • ICD-9 coded Procedures (up to 6 per claim) • Admission diagnosis code • Diagnoses and procedures are consistent with DRG. However, not all DRGs require specific diagnoses
Example: AMI • Almost all persons with primary discharge diagnosis of 410 have following DRGs: • 231-236: CABG with PTCA • 237-238: Major Cardiovascular Procedure • Diagnosis, procedure and DRGs can be used to define distinct population
ICD-9 V codes • “Supplementary Classification of Factors Influencing Health Status and Contact with Health Services” • 23% of hospitalizations have some V code • 2.8% have a V code as their primary reason for hospitalization • Examples: • V56.0 Renal dialysis • V58.1 Chemotherapy • V58.61 Long-term use of anticoagulants • V59.4 Kidney donor • V67.4 Follow-up examination after treatment of a fracture • V70.2 General psychiatric examination
Hospital Charges& Payments • MedPAR contains 34 fields describing charges • Total charges • Total accommodation charges • Total departmental charges • Specific charges for accommodation sub-types and specific departments or groups of departments • Patient’s payments • Inpatient deductible • coinsurance amount • CMS • total reimbursements • bill total per diem • Primary Payer (other than CMS) amount
Estimating Payments from MedPAR • Total paid by CMS: • total reimbursements + bill total per diem • Total paid by the beneficiary: • inpatient deductible + coinsurance amount+blood deductible • Total paid by all sources: • total reimbursement+ bill total per diem + inpatient deductible + coinsurance amount +blood deductible + primary payer amount • Note: Physician charges/payments are not in the MedPAR
Charge/Reimbursement Ratio • Most hospitals are on Prospective Payment systems (PPS) • per stay payment based on DRG (include labor and non-labor cost, with some geographic and risk adjustment) • Claim PPS_IND_CD • Charge and reimbursement ratio for specific hospitals may not be meaningful • But population wise, we often use this (or derived) ratio to obtain estimated payment in hospital discharge data (e.g., cost/discharge ratio)
Categorized Cost Variables In MedPAR • Cost unit: e.g., • Intensive care unit indicator • Coronary care unit indicator • Diagnostic Radiology • CT/MRI • DME use • Indicators for certain service use: • Pharmacy • Physical therapy • Laboratory • Emergency room
Discharge Destination • Information provided by hospital • Home/self care • Other short-term general hospital • Skilled nursing facility (SNF) • Intermediate care facility • Other institution • Home health service care • Left AMA • Home IV drug therapy • Died
Additional Comments on MedPAR • People admitted to hospitals through ER or outpatient visit (planned or unplanned) will appear in MedPAR/inpatient SAF, often not in the outpatient claims • Check admission type variable • Info in MedPAR is care received, not care needed • Some disease diagnoses may be missing, or some conditions may not be diagnosed or recorded (e.g., hypertension) • Combining with other claims, MedPAR is often a start point (e.g., studying the follow up care for those with CABG surgery)
Outpatient Claim File • Facility claims, use UB-92 /04 forms • Data structure is the same as inpatient SAF • CMS provides data in two files: • Base claim • Revenue centers (detailed info and charge) • Can be linked by bene_id and claim_id • If you request CCW data • Chronic condition files: condition, span and health care cost/values