California Workers' Compensation Institute

Introduction to CWCI's Cumulative Trauma Claim Interactive Research Application

8/21/2025

As a corollary to CWCI's ongoing research on CT claims, the Institute developed an interactive research application that members can use to examine CT claim trends in California and to build customized views of CT claim data, which is presented in a series of seven data dashboards. This Interactive Research Report serves as an introduction and users guide to the app, providing details on how to access it, the data and methods used to develop it, and the content of each dashboard, including screenshots and descriptions of the various metrics and filters that are available.

Legislative Impact Analysis: SB 632

7/08/2025

A CWCI Legislative Impact Report examines SB 632, a bill that would give acute care hospital workers who provide direct patient care presumptions of compensability for 9 categories of injuries, encompassing more than 250 ICD-10 codes.

Long COVID-19 Claim Characteristics and Treatment in California Workers' Compensation

6/03/2025

CWCI's analysis examines the various characteristics of Long COVID claims in California workers' compensation, including the distribution of claims by diagnostic category and affected body part, the mix of treatment payments among medical service categories at different points of development, and demographic differences between Long COVID and shorter duration COVID claims. The Research Note is posted under the Research tab and is available to CWCI members and subscribers who log in. Others can purchase a copy from the Store.

CWCI Updates Inpatient Hospital Utilization Application and Issues Interactive Research Report

1/16/2025

A CWCI Interactive Research Report based on the latest update to the Institute's Inpatient Hospital Utilization Application which now includes inpatient hospital discharge data for CY 2012 through CY 2023 compiled by the California Department of Health Care Access and Information (HCAI). The report provides a refresher on how the application is formatted and can be used, and highlights some of the latest results and trends, including data that can be used to track and compare changes in the volume of inpatient hospitalizations paid under California workers' compensation, Medicare, Medi-Cal, and private coverage since 2012.

The Impact of Medical Inflation on California Workers' Compensation

11/18/2024

A new CWCI Report to the Industry explores how medical inflation impacts allowable fees under the California Official Medical Fee Schedule (OMFS).

Opioid Prescribing for Injured Workers Covered by California Workers Compensation System and Other Payers: 2017-2023

10/22/2024

A CWCI Report to the Industry analyzes 2017-2023 opioid prescription data extracted from the California Department of Justices Controlled Substance Utilization Review and Evaluation System (CURES) database to track opioid utilization in the state, noting the percentage change in the number of opioid patients overall and within the workers compensation system from 2017 through 2023. The report measures changes in the average strength of the daily dose of morphine equivalents (the morphine equivalent dose or MED) and the average duration of opioid use for workers comp opioid patients and compares the results to the treatment guideline recommended levels to identify the proportion of patients whose opioid use exceeded guideline recommendations and how these proportions changed over time.

Are Migraine Drugs Becoming a New WC Rx Cost Driver?

10/04/2024

Are Migraine Drugs Becoming a New WC Rx Cost Driver? A new CWCI study looks at recent increases in the utilization and reimbursement of Migraine Drugs in California workers' compensation and highlights 6 high-cost brand drugs that have helped fuel that growth.

CWCI Claims Monitoring Interactive Report

8/28/2024

A report highlighting recent results and trends from the latest update to CWCI's Claims Monitoring Interactive Application which features AY 2009 - AY 2023 data (valued as of December 2023) on average medical payments, average paid indemnity, and combined medical and indemnity payments at nine levels of development ranging from 3 months to 72 months post injury. The report also provides a refresher on how the Application is formatted and how CWCI members can use it.

Increased Medical-Legal Costs and Current QME Supply -- Impact of the 2021 Medical-Legal Fee Schedule

6/27/2024

CWCI's updated analysis of the impact of the new Med-Legal Fee Schedule based on data through October 2023.

Legislative Impact Analysis: SB 1299

6/17/2024

A CWCI Legislative Impact Report examines the issues surrounding SB 1299, a bill that would give farmworker heat-related injury claims a presumption of compensability if the employer is found non-compliant with Cal/OSHA's outdoor heat standard.

Analysis of Cumulative Trauma & Litigated Claims in California Workers' Comp

3/01/2024

CT & Litigated Claims in California Workers' Comp. A CWCI Research Note based on 1.4 million claims with claims administrator notification dates ranging from 2010 through 2022 tracks the growth of CT claims in California workers' compensation and examines the impact that factors such as region, tenure, industry, age, and average weekly wage have on the likelihood of CT claims.

CWCI Analysis of California WC Inpatient Care, 2012-2022

1/31/2024

A CWCI Research Update report uses HCAI data to monitor trends in the utilization of inpatient care in California workers comp from 2012 through 2022, comparing the workers comp trends to those in Medicare, Medi-Cal and private coverage. The report also reviews changes in the types of conditions treated and the services delivered to injured workers before and after the pandemic was declared in 2020; takes a focused look at the primary diagnoses underlying inpatient hospitalizations involving spinal fusions and major joint replacement surgeries; and examines how the growth of outpatient surgery is affecting the total number of injured worker hospitalizations.

Claims Monitoring: Medical and Indemnity Development, AY 2013 - AY 2022

9/25/2023

A CWCI analysis of data from the IRIS database tracks average California workers' comp total losses per indemnity claim since the implementation of SB 863 through the first three years of the pandemic, and breaks out the data to show both paid medical and paid indemnity loss trends. The study also looks at 24-month loss trends for claims from five key industry sectors and for claims from injured workers living in 7 distinct regions of the state as well as from workers living out of state.

Cost-Driver Medications in the Top California Workers' Comp Therapeutic Drug Groups: Part 3, Musculoskeletal and Ulcer Drugs

7/13/2023

The final report in a 3-part research series on workers' compensation medications that represent a relatively small share of the dispensed prescriptions within their therapeutic drug group, but due to their high average reimbursements, account for a disproportionate share of the total drug spend within their group. Part 3 of the series focuses on Musculoskeletal and Ulcer Drugs.

An Analysis of AB 1213's Proposed Change to the 104-Week TD Cap

6/14/2023

CWCI examines a proposal to alter the TD cap by excluding TD that is paid or due from the UR treatment denial date to the date of the treatment authorization if the denial is overturned by IMR or the WCAB. The analysis estimates the percentage of claims that would be affected by the proposal in light of the required IT costs to update claims systems and the ongoing administrative costs for manual processes to identify and track claims with TD payments and UR and IMR activity.

Cost-Driver Medications in the Top California Workers' Comp Drug Groups: Part 2, Dermatologicals, Opioids, and Antidepressants

5/22/2023

The second in a 3-part research series on workers' compensation medications that represent a relatively small share of the dispensed prescriptions within their therapeutic drug group, but due to their high average reimbursements, account for a disproportionate share of the total drug spend within their group. Part 2 of the series focuses on Dermatologicals, Opioids, and Antidepressants.

CWCI Report to the Industry Examines Factors that Drive IMR Volume and Outcomes

5/12/2023

A new CWCI Report to the Industry provides an in-depth look at the dispute resolution process in California workers compensation and examines IMR activity and outcomes from 2014 through 2022.

Patterns in the Provision of Professional Medical Services in California Workers Compensation

3/20/2023

CWCI research tracks changes in the prevalence and volume of professional medical services in the first 2 years of treatment for indemnity claims in which medical care began between 2014 and 2019. To examine the impact of the pandemic, the authors compare the prevalence and volume of services in the first 6 months of treatment for claims in which treatment began in 2018 and 2019 claims in which treatment began in 2020 and 2021. In both cases, results are broken out for claims with and without surgery.

Cost-Driver Medications in the Top California Workers' Comp Drug Groups: Part 1, Anti-Inflammatories & Anticonvulsants

2/27/2023

The first of a 3-part research series on workers' compensation medications that represent a relatively small share of the dispensed prescriptions within their therapeutic drug group, but due to their high average reimbursements, account for a disproportionate share of the total drug spend within their group. Part I of the series focuses on Anti-Inflammatories and Anticonvulsants.

Trends in the Utilization of Inpatient Care in California Workers' Compensation

1/04/2023

A Research Update report that continues CWCIs series of studies examining inpatient utilization trends using data compiled by the California Department of Health Care Access and Information. The analysis compares the volume and types of inpatient hospitalizations covered by workers compensation to those covered by Medicare, Medi-Cal, and private coverage.