Press Release


Bob Young

For Release:

September 15, 2022

CWCI Reports Continued Decline in IMR Volume in the First Half of 2022

Oakland, CA – After hitting a record low in 2021, the number of independent medical reviews (IMRs) used to resolve California workers’ comp medical disputes continued to decline in the first half of 2022 according to new data from the California Workers’ Compensation Institute (CWCI).     

Under California law, every workers’ comp claims administrator must have a Utilization Review (UR) program to ensure that the treatment provided to injured workers is supported by clinical evidence outlined in the state’s Medical Treatment Utilization Schedule (MTUS) or other applicable guidelines.  Most treatment requests are approved by UR, but in 2012 state lawmakers adopted IMR to allow injured workers to obtain an independent medical opinion on requests that UR physicians deny or modify.  IMR took effect for all claims in July 2013, and CWCI began monitoring IMR activity in 2014.  CWCI’s latest review shows that 62,859 IMR decision letters were issued in the first half of this year in response to applications submitted to the state, down 7.6% from 68,039 letters issued in the first six months of 2021, while the latest full-year count shows 133,494 letters issued in 2021, down 2.4% from 136,738 letters in 2020 and down 27.7% from the all-time high of 184,735 letters in 2018. 

IMR letters often include decisions on multiple medical service requests, and as the volume of letters has declined in recent years, the number of service decisions has dropped as well.  In 2019, the last year prior to the pandemic, IMR physicians issued medical necessity decisions on 261,708 primary service requests, but by 2020 that had fallen 17.5% to 215,788 decisions, and in 2021 it continued down, falling to 209,782.  The latest data show that in the first half of 2022 IMR physicians issued 97,649 decisions on primary medical service requests. 

The distribution of IMRs by type of medical service request show that since peaking in 2018, IMR letter counts have declined across all medical service categories, but most of the overall decline in IMR can be traced to the sharp decline in prescription drug disputes that occurred after the state incorporated the Chronic Pain and Opioid Guidelines into the MTUS in late 2017 and implemented the MTUS Prescription Drug Formulary in January 2018.  In the wake of those changes, disputes over prescription drug requests dropped from 47.3% of all IMRs in 2017 to 34.9% of all IMRs in 2021, with the latest data showing prescription drug disputes were down to 33.9% of the IMR disputes in the first half of this year.  Meanwhile, disputes involving other types of medical services have accounted for an increasing share of the IMRs, as their IMR volume declined far less than the decline in prescription drug disputes. As a result, since 2015, requests for physical therapy increased from 8.7% to 13.3% of the IMRs; requests for injections increased from 7.0% to 12.4%; and requests for acupuncture more than doubled from 2.2% to 4.6%.  

After reviewing medical records and the other information provided to support a treatment request, IMR physicians upheld the UR physician’s modification or denial of the medical service in 91.3% of the IMRs in the first half of 2022, down just slightly from the 92.0% uphold rate for all of 2021.  The uphold rates for specific service categories continue to vary, however, ranging from 81.4% for psych services to 95.6% for injections.

The latest update also shows that a small number of physicians continued to account for a disproportionate share of the disputed medical service requests that went through IMR this year and drive much of the IMR activity in the system.  The top 10% of physicians identified in the IMR decision letters issued in the 12 months ending in June 2022 (811 doctors) accounted for 82.8% of the disputed service requests during that period, while the top 1% (81 doctors) accounted for 39.8%.

CWCI has published additional data and analyses on the IMR data through June 2022 in a Bulletin which Institute members and subscribers will find under the Communications tab at  CWCI members can also access additional graphics by using their log-in and password information then going to the drop-down menu under the Research tab at the top of the home page and clicking “Independent Medical Review.”  

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