Treating Facility, Provider Patient Volume and Sharing Influence Survival of MM Patients

A study published by the official journal of the National Comprehensive Cancer Network (NCCN) has found that where patients with multiple myeloma (MM) are treated and whether the facility treats many patients with MM can impact survival.

The population-based study investigates a previously identified group of patients that share a common characteristic, or several. Disease risk, drug response, survival, even cancer type can serve as a survey’s backbone.

Using this study method and claims-based data, researchers from BC Cancer in Victoria, British Columbia, Canada, and the Lineberger Comprehensive Cancer Center and Gillings School of Public Health in Chapel Hill, North Carolina, recently investigated 2 theories among patients with MM¹:

1. Patients evaluated at an National Cancer Institute--designated Comprehensive Cancer Center (NCICCC) have a longer overall survival (OS) compared with those assessed elsewhere.
2. Treatment by high- or low-volume providers who share patients with an MM specialist improves survival.

Their results were published in a recent issue of Journal of the National Comprehensive Cancer Network.

For their study, the authors wanted to expand on previous research results that suggest outcomes are improved among patients with MM treated at high-volume facilities. They said they wanted to learn more about “the relative contribution of provider expertise and hospital resources to improved outcomes,” which were unknown at the time.¹

Notably, leaders of community oncology clinics have resisted the argument that treatment at academic medical centers results in better outcomes, saying that many community practices can offer access to clinical trials at a lower cost with less travel burden on patients.

Patients were identified using the University of North Carolina Cancer Information and Population Health Resource (CIPHR). They had to be aged 18 or older and received their MM diagnosis between 2006 (when Medicare Part D became available) and 2012 (most recent complete year of data available when the study was done). The patient exclusion criteria were extensive, and they included additional cancer diagnoses, incomplete CIPHR data on home or provider ZIP code, a lack of continuous insurance coverage for the 6 months before and 12 months after diagnosis, chemotherapy not received in the 12 months following diagnosis, and simultaneous coverage with Medicare, Medicaid, and private insurance. These, and others, resulted in a study population of 1029 patients, with a mean age of 68 years.

Treating facility, provider volume, and patient sharing between MM specialists and community providers were investigated for their effects on patient survival. For treating facility, a patient had to have at least 1 outpatient visit in the year after diagnosis to an NCICCC oncologist, and provider volume was defined as number of patients with MM per provider in the 2 years before diagnosis. Patient sharing was 2-fold:

1. NCICCC oncologists: Two had to have at least 1 patient with MM in common in the 2 years before diagnosis.
2. Community oncologists: They had to share at least 10% of their patients with an NCICCC MM specialist.

Covariates were age, sex, race, marital status, insurance type, distance between home and NCICCC clinic, hospital referral region, activities of daily living dependency score, rural versus urban zip code, and sociodemographics (quartiles of median household income, percentage of population unemployed, percentage of population with college degree).

NCICCC MM specialists who were the primary treating physicians for patients with MM and evaluation at an NCICCC meant lower mortality risk for patients. There was a 22% higher risk of death after treatment at the lowest-quartile facilities (less than 4 new patients with MM per year) compared with the highest quartile (at least 10 new patients/year). And mortality risk was higher among patients treated by community oncologists; high- and low-volume status and patient-sharing history made no difference. Mortality rates were equal, however, between patients who received treatment from NCICCC MM specialists and the highest-volume community oncologists.

The study authors say these results add to an already strong body of evidence that “patients with MM benefit from care at high-volume facilities, and suggest that similar outcomes can be achieved by the highest-volume providers in the community.” To improve outcomes among these providers, the authors suggest earlier adoption of new drugs, earlier recognition of problems and progressive disease, and quick access to nononcology specialties (eg, orthopedics, nephrology). They also believe that any patient-sharing with an MM specialist is beneficial, because of the rarity of MM.

Possible study limitations included lack of coverage of other survival factors, including disease stage, cytogenetics, and clinical trial involvement; a likely incomplete definition of patient-sharing; treatment regimens incorrectly noted or misclassified due to varying degrees of claim specificity; and not being able to gauge provider patient volume correctly.

References

1. Freeman AT, Kuo M, Zhou L, et al. Influence of treating facility, provider volume, and patient-sharing on survival of patients with multiple myeloma. J Natl Compr Canc Netw. 2019;17(9):1100-1108. doi: 10.6004/jnccn.2019.7298.