August 01, 2014
5 min read

Patient-reported outcomes move into clinical practice

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Patient-reported outcome measures using validated, standardized, patient questionnaires have been extensively used in orthopedic research for many years and are now increasingly incorporated into clinical practice. Patient-reported outcomes are used to objectively measure a patient’s pain and function before and after treatment, and compare the scores to age-matched controls.

Most orthopedic patients undergo elective surgery to relieve pain and improve physical function. Patient-reported outcomes (PROs) measure the patient’s pain and physical function before and after surgery or any other type of treatment intervention. These scores enable the surgeon and the patient to objectively evaluate the patient’s pain and function in comparison to age-matched controls and to determine optimal clinical care according to the severity of the symptoms.

Beyond research, PROs are increasingly used in total joint replacement (TJR) registries, for quality reporting and pay-for-performance (P4P) opportunities. An example of such reporting already in place includes the CMS Physician Quality Reporting System (PQRS) and Blue Cross of Massachusetts P4P pilot program for TJR. International arthroplasty registries are already using PROs in surveillance for suboptimal TJR outcomes, new payment reforms and assessment of TJR value. Value is defined as patient outcome divided by cost. In order to assess value, orthopedists, hospitals and third-party payers must have accurate measurement of outcomes of treatment; most are choosing PROs in order to measure the numerator for the value equation. The CMS PQRS is a voluntary individual reporting program that provides an incentive payment to identified eligible professionals who satisfactorily report data on quality measures for covered physician fee schedule services furnished to Medicare Part B beneficiaries.

David Ayers

David C. Ayers

The FORCE-TJR registry is a qualified TJR registry that submits TJR PRO data to CMS for physicians who are member of FORCE-TJR and routinely enter TJR patient data. FORCE-TJR members are eligible for CMS bonus payments based upon the data submitted by FORCE-TJR on their behalf. Private insurance companies are also offering physician’s incentives to collect and submit TJR PRO data. Blue Cross of Massachusetts is conducting a pilot program in which orthopedic surgeons receive an incentive payment for submitting PRO data on primary total hip replacement and another for PRO data on primary total knee replacement (TKR).

Types of PROs

Orthopedic surgeons typically use a combination of two types of PRO measurement tools: a general health index PRO and a disease- or joint-specific PRO. In joint replacement surgery, the general health index is typically the SF-12, SF-36 or PROMIS Global. These general health PROs are used in all types of patients regardless of their medical condition. The SF-36 is a short-form 36-item health questionnaire, from which summary scores that quantify physical function and emotional function can be calculated. The physical function summary score quantifies the patient’s ability to perform tasks of daily living and is called the SF-36 physical component score (PCS). The second summary score quantifies the patient’s emotional function and is called the SF-36 mental component score (MCS). The MCS evaluates the patient’s emotional health and is affected by the presence of depression, anxiety, poor coping mechanisms and low levels of social support. Numerous reports have illustrated that orthopedic patients with low (less than 40) preoperative MCS are at risk for poorer improvement in their physical function after TJR. Another general health PRO is the NIH-funded Patient Reported Outcomes Measurement Information System (PROMIS) that is establishing a generic core set of PROs, a-nine item bank that will be ultimately available through the Internet and smart phones to reach large numbers of patients. Some PROs provide only one score and do not offer the ability to separate physical function summary score and emotional summary score. An example is the EQ-5D, or EuroQoL, commonly used in Europe, but rarely used in the United States.

Other PROs are measures that are specific to a disease, medical condition or anatomic body part and have been validated in specific patient population. For instance, the proprietary WOMAC has been validated in patients with osteoarthritis, including those undergoing total hip and total knee replacement. The WOMAC assesses clinical changes (pain, stiffness and function) over time. The Hip Osteoarthritis Outcome Scale (HOOS) and the Knee Osteoarthritis Outcome Scale (KOOS) are also used in patients undergoing TJR or TKR, respectively, and include the WOMAC items plus additional items. The non-proprietary HOOS and KOOS include subscores for pain, symptoms, activities of daily living, sport/recreation function and quality of life. In the HOOS/KOOS pain, for instance, a patient reports how much pain he/she experiences while performing activities of daily living. The Oxford hip or knee score is a proprietary disease-specific score that sums the severity of pain and functional limitation in TJR patients into one score. A limitation of this is the inability to distinguish less-than-expected pain relief from limited function gains in a patient with a low postoperative score. The use of PROs that can provide a pain score and a separate function score is beneficial to accurately assess these two important issues separately.

Anthony DiGioia

Anthony M. DiGioia III,

The timing of the PRO collection is an important consideration. PROs can provide valuable objective data for both the surgeon and the patient in order to make an informed shared decision as to when to proceed with elective TJR surgery. For example, the mean preoperative SF-36 PCS score for U.S. patients who elect to proceed with TJR is 32, whereas the mean score for age-matched control patients is 50. The standard deviation is 10 for the SF-36 and SF-12. Thus, patients electing TJR are almost two standard deviations below the physical function mean for age-matched controls, which indicates significant limitations in their physical function as a result of their advanced arthritis. TJR registries recommend obtaining PROs 1 month or 2 months prior to surgery in order to document accurately the patient’s level of preoperative pain and function. Postoperatively, PROs are collected at 6 months and 12 months to quantify the level of pain relief and improved physical function after TJR.

Important role of registries

Collecting PROs has been greatly simplified by registries such as FORCE-TJR, which provides turn-key software platforms to collect PROs. Methods of collection are now typically electronic and based on an Internet platform. This gives patients flexibility to submit their information either weeks in advance of their office appointment, while in the waiting room at their follow-up appointment, or while at home if they choose not to return for a follow-up appointment or change to a different hospital or surgeon provider, or move to a different insurance plan or a different state. Registries such as FORCE-TJR also collect extensive patient demographic information, complete medical and orthopedic comorbid conditions, all pertinent surgical information, adverse events, readmissions and revisions. This enables mature registries to provide participants with access to their own data, and to risk adjust the results in order to allow fair and accurate comparisons to other surgeons’ practices or, when the data is aggregated, to other hospitals. Risk adjustment of PRO data, complication data and readmission data is important as not all patients and not all surgeons’ practices are the same.

A TJR registry that provides participating surgeons access to their own data as well as an ability to compare their data to national standards is extremely valuable. It also allows surgeons to see their own data before it is published in numerous public reporting programs such as CMS or state-focused infection websites. Surgeons interested in learning more about TJR registries or opportunities to collect PROs in their patients, in order to participate in PQRS reporting or private payer P4P bonus opportunities, may refer to the FORCE-TJR website at

Ayers DC. Clin Orthop Relat Res. 2013;doi: 10.1007/s11999-013-3143-z.
Franklin PD. JAMA. 2012;doi:10.1001/jama.2012.12568.
For more information:
David C. Ayers, MD, can be reached at University of Massachusetts Medical School, 55 Lake Ave. North, Worcester, MA 01655; email:
Disclosure: Ayers certifies that he, or a member of his immediate family, has no funding or commercial associations (e.g., consultancies, stock ownership, equity interest, patient/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article.