Friday, June 9, 2017

Documenting shoulder comfort and function in the context of a busy practice

Is the Simple Shoulder Test a valid outcome instrument for shoulder arthroplasty?

It is in the interest of all shoulder surgeons to document the functional status of their patients before and sequentially after treatment to learn what treatments are working for which diagnoses in which patients. Observing one's personal outcomes is a great way for a surgeon to continue to improve. The issue is that many of the existing instruments are time consuming, at risk for observer bias, unvalidated, and/or inflexible in terms of the patient's need to return to the office for evaluation.

These authors point out that the Simple Shoulder Test (SST - a 12 item 'yes' or 'no' questionnaire) is a brief, inexpensive, convenient, and widely used patient-reported outcome tool. Since it is the patient who should be served by our treatment, it makes sense to base the outcome assessment on the patient's self-assessed ability to perform shoulder functions.

The results are easy to record in the patient's medical record so that the trend over time can be easily followed. The12 individual questions of the SST allow a more detailed discussion of each patient's functional deficits and the likelihood that the desired function might be restored.

The SST does not require any potentially biasing participation by physicians, nurses, or therapists; it can be completed without a computer and without the patient’s having to return to the surgeon’s office. It has been adapted and validated in multiple languages, including Persian, Spanish, Portuguese, Dutch, and Turkish.

However, the SST has not been rigorously evaluated for patients treated with shoulder arthroplasty. The goal of their study was to rigorously evaluate the validity of the SST for outcome assessment in shoulder arthroplasty using a systematic review of the literature and an analysis of its properties in a series of 408 surgical cases. For these patients the authors documented SST scores, 36-Item Short Form Health Survey scores, and satisfaction scores collected preoperatively and 2 years postoperatively. The responsiveness of the SST was assessed by comparing preoperative and 2-year postoperative scores. The criterion validity of the SST was determined by correlating the SST with the 36-Item Short Form Health Survey. The construct validity of the SST was tested through 5 clinical hypotheses regarding satisfaction, comorbidities, insurance status, previous failed surgery, and narcotic use.

They found that scores improved from 3.9 ± 2.8 before arthroplasty to 10.2 ± 2.3 after arthroplasty (P < .001). The change in SST correlated strongly with patient satisfaction (P < .001). The SST had large Cohen’s d effect sizes and standardized response means. Criterion validity was supported by significant differences between satisfied and unsatisfied patients, those with more severe and less severe comorbidities, those with workers’ compensation or Medicaid and other types of insurance, those with and without previous failed shoulder surgery, and those taking and those not taking narcotic pain medication before surgery (P < .005).

They concluded that these data combined with a systematic review of the literature demonstrated that the SST is a valid and responsive patient-reported outcome measure for assessing the outcomes of shoulder arthroplasty.

Comment: A figure from this paper helps to make a point. The black arrows in the figure below indicate patients who did not fare so well after shoulder arthroplasty. These are the ones on which the surgeon needs to focus, asking - was the type of arthroplasty the right treatment, was it done well, was the rehab properly organized, were there other factors interfering with the desired outcome?

The SST can also be useful in discussing with the patient "when is it the right time for a shoulder replacement for arthritis?" This question comes up often.

Of course, the answer depends on many things, including the degree to which the quality of life of the individual is impaired by the shoulder condition, the condition of the muscles, tendons, bone and nerves around the shoulder, the expectations of the patient, the overall health of the individual, the individual's willingness to accept the risks of surgery, and the degree of comfort the individual has with the surgeon.

We recently summarized the SST scores of over 2800 of our patients at the point where they had decided to have a shoulder joint replacement for their arthritis. The average preoperative SST score was 3.9. The numbers of patients with each of the 12 possible SST scores is shown below. Basically, this graph shows that 62% of patients having joint replacement had preoperative SST scores of 4 or below; 30% had SST scores from 5-8; and 8% had scores from 9-12.

We find this graph useful for allowing the patient to place their current self-assessed comfort and function in the context of other patients having shoulder arthroplasty.

One of the operations we offer to patients with shoulder arthritis is the ream and run procedure, a method of shoulder joint replacement arthroplasty that avoids the potential risks associated with a plastic socket.
The chart above shows how the Simple Shoulder Test (SST) is used to document the recovery of patient self-assessed comfort and function after a ream and run procedure for shoulder arthritis. The data represent the average recovery from a consecutive series of over 100 patients with at least two years of post surgical follow-up. The vertical axis represents the total number of SST questions answered 'yes', while the horizontal axis represents the years after surgery. The dots show individual data points and the lines show the average (plus or minus one standard deviation) for all the patients.
Since, on average, patients having the ream and run live over 500 miles from our center, routine office visits are impractical for them.  Because patients mail or email their results to us, we have been able to keep close tabs on their recovery using the Simple Shoulder Test.The full article was recently published in the JBJS and discussed in this post.

In conclusion, if "value" is defined as the benefit divided by the cost, the SST appears to be a high value assessment tool.