Minimal Clinically Important Difference, Substantial Clinical Benefit and Patient Acceptable Symptom State of PROMIS Upper Extremity following Total Shoulder Arthroplasty
These authors assessed the outcomes of 165 patients having shoulder arthroplasty using PROMIS Upper Extremity v2.0 (PROMIS UE). They determined the Minimal Clinically Important Difference (PROMIS MCID), Substantial Clinical Benefit (SCB), and Patient Acceptable Symptom State (PASS) of patient-reported outcome measures (PROM).
They calculated the anchor-based MCID for PROMIS UE was to be 8.05, the anchor-based SCB to be 10.0. The distribution-based MCID was calculated to be between 3.12 and 8.65. The PASS was calculated to be 37.2.
Comment: From this paper we can see that there are multiple ways to evaluate the outcome of shoulder arthroplasty. The primary value of a surgeon's documenting patient reported measures of comfort and function before and after surgery is to determine what procedures for which patients work best in his or her hands and to communicate this experience in terms that are understandable to patients.
Patients may have difficult grasping the concepts of PROMIS UE, MCID, PASS, and SCB.
We've found that an easier way to communicate the benefit to the patient of a procedure is to report the percent of maximal possible improvement. Patients can easily understand what 100% shoulder comfort and function represents. They can also understand that in the experience of their surgeon, the proposed treatment has improved comfort and function by, for example, 80% of what was possible.
Consider the data from One and two-year clinical outcomes for a polyethylene glenoid with a fluted peg: one thousand two hundred seventy individual patients from eleven centers.
The improvement expressed as a percent of maximum possible improvement (%MPI) is easily determined: (post op score - pre op score)/(perfect score - pre op score). In the study above, both the SST and the ASES scores showed an 80% improvement of the maximal possible improvement.
While MCID is a common way of looking at the amount of improvement, it has a problem. Consider two patient having a shoulder arthroplasty, each with an improvement of 3 in the SST score (both exceeding the published value of 2.4 for the MCID).
However, their outcomes are not the same as is shown by the %MPI:
Smith only improved by 27% of the maximal possible improvement, whereas Jones improved by 75% of the maximal possible improvement (even though the amount of improvement in both cases exceeded the MCID).
Other important considerations in selecting a method for assessing outcomes are:
(1) it should facilitate ongoing participation by the maximum number of patients (minimizing the percent of patients lost to followup while enabling the capture of data 5, 10 or more years after the procedure). The requirement that patients return for measurements (e.g. with the Constant score) or access to a computer (e.g. with the PROMIS system) may pose barriers to the desired followup.
(2) it should pose a minimal burden on office staff in scoring and data entry.
(3) it should provide data on specific functions that patients can easily comprehend, rather than a numerical value that may not have meaning to patients.
For these reasons we use the Simple Shoulder Test (see this link). (1) It is accessible and low tech - completable with pencil and paper from the patient's home without needing a computer connection or office visit
(2) It is simple to score (count the "yes" responses 0 to 12).
(3) It yields information patients can understand "does your shoulder allow you to sleep at night?"
How you can support research in shoulder surgery Click on this link.
Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link). How to x-ray the shoulder (see this link). The total shoulder arthroplasty (see this link). The ream and run technique is shown in this link. The cuff tear arthropathy arthroplasty (see this link). The reverse total shoulder arthroplasty (see this link). The smooth and move procedure for irreparable rotator cuff tears (see this link). Shoulder rehabilitation exercises (see this link).
Follow on twitter: Frederick Matsen (@shoulderarth)
