Physician-to-Population Ratio Analysis


Physician needs analysis is a tricky endeavor, but it is necessary for recruitment assistance, not-for-profit hospital community needs reporting, and anti-trust market analysis. The core of this analysis is focused on ratio of physicians-to-population for target specialties within the primary and secondary service market.

The physician needs analysis is one of the most difficult analyses that hospital outsource to consulting firms.  Published studies on the physician-to-population ratios are few and far between.  The last reputable study was published by Thomson Reuters in 2011.

The NPI data set and Medicare reassignment data set are two of the most detailed resources available for this type of analysis.  These resources includes detailed physician data for over 250 types of specialists, including all types of physicians, podiatrists, optometrists, chiropractors, dentists, nurse practitioners, and physician assistants.

Even with such robust data resources, the analysis is still very complicated and many adjustments and factors still need to be considered.

Factor #1: State-Level Analysis

HCTadvisor recommends analyzing state-level populations and provider counts to develop benchmarks, because the licenses to practice medicine are granted by each U.S. state.  Most physicians only practice in one state, and most patients do not cross state lines for medical care.  U.S. states are also generally large enough for the sample sizes to be meaningful.  The populations of individual counties can be too small for statistically meaningful analyses.

In regions where physicians and patients are relatively more mobile (New England, D.C.), you can group states together into regions to see if the migration patterns even out.

Factor #2: Puerto Rico

HCTadvisor strongly recommends excluding Puerto Rico data.  Puerto Rico is grossly under-served compared to the traditional 50 U.S. states and D.C.

Factor #3: Overlapping Services

This is a big one.  You may have to group and un-group several physician specialties, or even types of professionals, to account for regional variations in physician-to-population ratios.  Here are several examples of why this is necessary.

Overlap within major specialties:
  • A general orthopaedic surgeon will perform many of the same types of surgeries as orthopaedic sub-specialists focused on sports medicine, adult reconstructive surgery, spine surgery, hand surgery, and pediatric orthopaedic surgery. These ratio variations will even out as you look at whole specialty groups and larger markets.
Overlap between major specialties:
  • Family medicine physicians compete for some of the same patients as pediatricians, and internal medicine physicians compete for some of the same patients as family medicine.
  • The population ratios for pure hospitalists will vary depending on the number of primary care physicians in internal medicine who still round on hospital patients in each community.
  • Orthopaedic spine surgeons and neurosurgeons perform some of the same spinal surgeries.  An orthopaedic hand surgeon may perform many of the same surgeries as a plastic hand surgeon, and an orthopaedic foot & ankle surgeon may compete somewhat with some podiatrists.
Confounding effect of mid-levels, medical students & residents
  • Certain primary care and physician specialist ratios are affected by the number of nurse practitioners and physician assistants in the community.  NPs and PAs sub-specialize in ambulatory care and hospital-based disciplines too, so you can adjust your ratios accordingly.
  • Some medical students, interns, residents, and fellows are eligible for NPI numbers as healthcare providers.  If they are in a  position to prescribe medications for patients whose prescriptions are filled by pharmacies, refer patients to other healthcare providers, or order tests for patients, those pharmacies and other healthcare providers identify the physicians in training as prescribers or as providers who referred patients or who ordered tests for patients in their claims. You have to make a judgement call on what proportion of medical students and residents you want to count, if any.