{
  "version": 1,
  "generatedAt": "2026-09-07T04:32:07.308636+00:00",
  "data": [
    {
      "id": "melnickFonkych2016",
      "citation": "Melnick GA, Fonkych K. Inquiry. 2016;53:0046958016651555.",
      "doi": "10.1177/0046958016651555",
      "pmcid": "PMC5798729",
      "peerReviewed": true,
      "geography": "California statewide hospital sample",
      "period": "2004-2013",
      "population": "Commercial inpatient allowed payments from Blue Shield of California; about 230 hospitals in 2012",
      "priceConcept": "Case-mix-adjusted allowed payment per inpatient admission",
      "design": "Longitudinal hospital analysis with regression adjustment",
      "finding": "Prices per admission increased 76% across all hospitals. Adjusted prices increased 113% at hospitals in the two largest systems versus 70% at other hospitals; by 2012-2013 the large-system differential was $3,964 (25%).",
      "limitation": "One commercial payer, nominal prices, historical period, and observational design; the study does not establish that system membership alone caused the differential.",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC5798729/"
    },
    {
      "id": "zhuangShapiro2023",
      "citation": "Zhuang T, Shapiro LM, Baker LC, Kamal RN. Clin Orthop Relat Res. 2023;481(6):1061-1068.",
      "doi": "10.1097/CORR.0000000000002489",
      "pmcid": "PMC10194750",
      "peerReviewed": true,
      "geography": "One large California health system",
      "period": "March 2021 price files and 2021 CMS quality measures",
      "population": "Public insurer-negotiated facility prices for total joint arthroplasty; 22 hospitals, 18 with complete quality data",
      "priceConcept": "Payer-specific negotiated facility price for DRG 470",
      "design": "Cross-sectional descriptive and correlation analysis",
      "finding": "Across 18 hospitals, the overall mean negotiated price was $54,500 (SD $23,200); payer-type means ranged from about $20,300 for Medicaid to $78,800 for commercial out-of-network coverage. No tested price-quality correlation met the study's corrected significance threshold.",
      "limitation": "Single system, one procedure, posted prices rather than claims-paid amounts, incomplete quality data, and cross-sectional associations.",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10194750/"
    },
    {
      "id": "brodke2019",
      "citation": "Brodke DJ, Guo C, Aouad M, Brown TT, Bozic KJ. J Bone Joint Surg Am. 2019;101(24):2212-2218.",
      "doi": "10.2106/JBJS.19.00475",
      "pmcid": "PMC10799682",
      "peerReviewed": true,
      "geography": "California CalPERS and same-carrier comparison population",
      "period": "2009-2013; reference pricing began January 2011",
      "population": "2,023 CalPERS and 8,024 non-CalPERS total joint arthroplasty patients",
      "priceConcept": "Insurer and patient payments for hospital total joint arthroplasty",
      "design": "Difference-in-differences observational evaluation",
      "finding": "Reference pricing was associated with a 19-percentage-point increase in lower-priced hospital selection and a $5,067 reduction in mean insurer payment, while mean patient out-of-pocket payment increased $1,991; most measured quality indicators did not change significantly.",
      "limitation": "Employer PPO population, elective joint replacement, observational parallel-trends design, and policy effects are not a statewide hospital price level.",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10799682/"
    },
    {
      "id": "robinson2015",
      "citation": "Robinson JC, Brown TT, Whaley C, Finlayson E. JAMA Intern Med. 2015;175(11):1783-1789.",
      "doi": "10.1001/jamainternmed.2015.4588",
      "pmcid": "PMC10799681",
      "peerReviewed": true,
      "geography": "California CalPERS and Anthem comparison population",
      "period": "2009-2013; reference payment began January 2012",
      "population": "35,195 CalPERS colonoscopy episodes before/after and 258,616 Anthem comparison episodes",
      "priceConcept": "Allowed price for colonoscopy across hospital outpatient departments and ambulatory surgery centers",
      "design": "Difference-in-differences observational evaluation",
      "finding": "Reference payment increased use of low-priced facilities by 17.6 percentage points and reduced adjusted price by 21.0%; CalPERS reported $7.0 million (28%) lower spending over two years, with no statistically significant complication change.",
      "limitation": "Includes hospital and nonhospital sites, one purchaser and carrier, outpatient procedure only, and observational policy evaluation.",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC10799681/"
    },
    {
      "id": "farrell2010",
      "citation": "Farrell KS, Finocchio LJ, Trivedi AN, Mehrotra A. J Gen Intern Med. 2010;25(2):110-114.",
      "doi": "10.1007/s11606-009-1176-5",
      "pmcid": "PMC2837489",
      "peerReviewed": true,
      "geography": "353 California acute-care hospitals",
      "period": "Post-AB 1045 field experiment published 2010",
      "population": "Written estimate requests for hysterectomy, cholecystectomy, or screening colonoscopy from a hypothetical uninsured patient",
      "priceConcept": "Hospital-provided self-pay price estimate",
      "design": "Audit study",
      "finding": "Only 28% of hospitals responded. Estimates varied from $3,500-$65,300 for hysterectomy, $2,700-$36,000 for cholecystectomy, and $350-$5,805 for colonoscopy; 75% of estimates exceeded the median California Medicare reimbursement.",
      "limitation": "Estimates were often non-comparable, sometimes excluded physician fees, and do not represent negotiated insurer prices or actual paid claims.",
      "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC2837489/"
    }
  ]
}