Do Patient Sociodemographic Factors Impact the PROMIS Scores Meeting the Patient-Acceptable Symptom State at the Initial Point of Care in Orthopaedic Foot and Ankle Patients?
Authors: Bernstein David N. , Mayo Kiah , Baumhauer Judith F. , Dasilva Chris , Fear Kathleen , Houck Jeff R. 
Published: July 2019

Abstract

Background
Patient-reported outcome measures such as the Patient-Reported Outcomes Measurement Information System (PROMIS) allow surgeons to evaluate the most important outcomes to patients, including function, pain, and mental well-being. However, PROMIS does not provide surgeons with insight into whether patients are able to successfully cope with their level of physical and/or mental health limitations in day-to-day life; such understanding can be garnered using the Patient-acceptable Symptom State (PASS). It remains unclear whether or not the PASS status for a given patient and his or her health, as evaluated by PROMIS scores, differs based on sociodemographic factors; if it does, that could have important implications regarding interpretation of outcomes and fair delivery of care.

Questions/purposes
In a tertiary-care foot and ankle practice, (1) Is the PASS associated with sociodemographic factors (age, gender, race, ethnicity, and income)? (2) Do PROMIS Physical Function (PF), Pain Interference (PI), and Depression scores differ based on income level? (3) Do PROMIS PF, PI, and Depression thresholds for the PASS differ based on income level?

Methods
In this retrospective analysis of longitudinally obtained data, all patients with foot and ankle conditions who had new-patient visits (n = 2860) between February 2015 and December 2017 at a single tertiary academic medical center were asked to complete the PROMIS PF, PI, and Depression survey and answer the following single, validated, yes/no PASS question: “Taking into account all the activity you have during your daily life, your level of pain, and also your functional impairment, do you consider that the current state of your foot and ankle is satisfactory?” Of the 2860 new foot and ankle patient visits, 21 patient visits (0.4%) were removed initially because all four outcome measures were not completed. An additional 225 patient visits (8%) were removed because the patient chart did not contain enough information to accurately geocode them; 15 patients visits (0.5%) were removed because the census block group median income data were not available. Lastly, two patient visits (0.1%) were removed because they were duplicates. This left a total of 2597 of 2860 possible patients (91%) in our study sample who had completed all three PROMIS domains and answered the PASS question. Patient sociodemographic factors such as age, gender, race, and ethnicity were recorded. Using census block groups as part of a geocoding method, the income bracket for each patient was recorded. A chi-square analysis was used to determine whether sociodemographic factors were associated with different PASS rates, two-way ANOVA analyses with pairwise comparisons were used to determine if PROMIS scores differed by income bracket, and a receiver operating characteristic (ROC) curve analysis was performed to determine PASS thresholds for the PROMIS score by income bracket. The minimum clinically important difference (MCID) for PROMIS PF in the literature in foot and ankle patients ranges from about 7.9 to 13.2 using anchor-based approaches and 4.5 to 4.7 using the ½ SD, distribution-based method. The MCID for PROMIS PI in the literature in foot and ankle patients ranges from about 5.5 to 12.4 using anchor-based approaches and about 4.1 to 4.3 using the ½ SD, distribution-based method. Both were considered when evaluating our findings. Such MCID cutoffs for PROMIS Depression are not as well established in the foot and ankle literature. Significance was set a priori at p < 0.05.

Results
The only sociodemographic factor associated with differences in the proportion of patients achieving PASS was age (15% [312 of 2036] of patients aged 18-64 years versus 11% [60 of 561] of patients aged ≥ 65 years; p = 0.006). PROMIS PF (45 ± 10 for the ≥ USD 100,000 bracket versus 40 ± 10 for the ≤ USD 24,999 bracket, mean difference 5 [95% CI 3 to 7]; p < 0.001), PI (57 ± 8 for ≥ USD 100,000 versus 63 ± 7 for ≤ USD 24,999, mean difference -6 [95% CI -7 to -4]; p < 0.001), and Depression (46 ± 8 for the ≥ USD 100,000 bracket versus 51 ± 11 for ≤ USD 24,999, mean difference -5 [95% CI -7 to -3]; p < 0.001) scores were better for patients in the highest income bracket compared with those in the lowest income bracket. For PROMIS PF, the difference falls within the score change range deemed clinically important when using a ½ SD, distribution-based approach but not when using an anchor-based approach; however, the score difference for PROMIS PI falls within the score change range deemed clinically important for both approaches. The PASS threshold of the PROMIS PF for the highest income bracket was near the mean for the US population (49), while the PASS threshold of the PROMIS PF for the lowest income bracket was more than one SD below the US population mean (39). Similarly, the PASS threshold of the PROMIS PI differed by 6 points when the lowest and highest income brackets were compared. PROMIS Depression was unable to discriminate the PASS.

Conclusions
Discussions about functional and pain goals may need to be a greater focus of clinic encounters in the elderly population to ensure that patients understand the risks and benefits of given treatment options at their advanced age. Further, when using PASS in clinical encounters to evaluate patient satisfaction and the ability to cope at different symptom and functionality levels, surgeons should consider income status and its relationship to PASS. This knowledge may help surgeons approach patients with a better idea of patient expectations and which level of symptoms and functionality is satisfactory; this information can assist in ensuring that each patient’s health goal is included in shared decision-making discussions. A better understanding of why patients with different income levels are satisfied and able to cope at different symptom and functionality levels is warranted and may best be accomplished using an epidemiologic survey approach.

Level of Evidence
Level III, diagnostic study.