Foot & Ankle International - September 2019 - 1010

1010
ankle surgery compared to patients with lower levels of preoperative PROMIS anxiety.
We sought to better understand the clinical relevance of
our statistically significant findings. To do so, we relied
upon data from Ho et al,9 who previously defined the MCID
thresholds in foot and ankle conditions for various PROMIS
tools, including physical function (4.2) and pain interference (3.7). Applying these thresholds to our data, it appears
that patients with higher preoperative PROMIS anxiety
scores achieved MCID for PROMIS pain but not for physical function. For patients with lower preoperative PROMIS
anxiety scores, MCID was also met for pain but not for
physical function. Taken together, PROMIS pain interference was the only measure to achieve MCID in both groups
based on preoperative PROMIS anxiety level. Further, the
difference in mean postoperative PROMIS pain interference scores between groups (5.7) also achieved MCID.
Stated differently, it appears that PROMIS pain scores for
both groups have meaningful improvements with surgery;
however, patients with higher preoperative anxiety continue
to have residual pain postoperatively that is of likely clinical significance. For example, postoperative PROMIS pain
interference scores in patients with higher preoperative
emotional distress were 58.6, nearly 1 SD more than the
general US population. Patients with higher preoperative
anxiety may benefit from counseling that their postoperative pain-while significantly improved from before surgery-may remain at higher levels compared to the average
patient.
Few studies in orthopedics have used the PROMIS anxiety tool.4 Here, we defined the MCID for PROMIS anxiety
at 5.3. Applying this threshold to our data, it appears that
PROMIS anxiety scores decreased in both groups, demonstrating that this measure (ie, PROMIS anxiety) has the
capacity to change with surgery. Yost et al reported a minimally important difference (MID) range of 3.0 to 4.5 in cancer patients.25 Future work needs to assess the impact of
emotional distress on patient satisfaction,6 as has been
implicated in total joint arthroplasty1 as well as foot and
ankle outcomes.2
Our study has limitations. Based on our data, 59 of 205
patients (29%) had PROMIS anxiety scores that correlated
with clinically impactful levels of anxiety, according to the
corresponding GAD-7 scores. Prior work demonstrated that
17% of patients presenting with upper extremity complaints
exceeded PROMIS anxiety thresholds5; our study population, then, may have a disproportionately higher prevalence
of anxiety conditions compared to other orthopedic conditions. However, recent evidence demonstrated that approximately 30% of patients with chronic foot and ankle disorders
had evidence of anxiety.16 These data are consistent with our
findings, suggesting that foot and ankle patients may exhibit
more anxiety than other orthopedic conditions. In addition to
PROMIS data, we did not gather traditional outcomes

Foot & Ankle International 40(9)
instruments related to foot and ankle disability (ie, the Foot
and Ankle Ability Measure [FAAM]) or anxiety-specific
domains (ie, GAD-7). We presume our findings would have
been similar if we compared patient groups according to
GAD-7 scores given the association between PROMIS anxiety levels and GAD-7 scores,20 but that is speculative. Our
study population was heterogeneous as patients underwent a
variety of foot and ankle procedures. It is possible that if we
created a homogenous study population, the impact of
PROMIS anxiety could vary depending on the foot and ankle
diagnosis/condition. Additionally, our estimation of an MCID
for PROMIS anxiety as one-half of the measured SD is specific to our sample may not be generalizable to other study
populations. Further investigations into an MCID for this
metric are needed and would best be performed with a larger
sample size. Lastly, operative anxiety may be associated with
patient characteristics such as race, income, and education
level. We did not have these data available for a more indepth analysis of our study cohort.
In conclusion, patients with higher preoperative emotional distress-as measured by PROMIS anxiety scores-
had more pain and less function following elective foot and
elective surgery. The residual difference in pain scores
between patients with higher and lower preoperative emotional distress is likely clinically meaningful and needs further investigation.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with
respect to the research, authorship, and/or publication of this article. ICMJE forms for all authors are available online.

Funding
The author(s) received no financial support for the research,
authorship, and/or publication of this article.

ORCID iD
Sandra E. Klein, MD,

https://orcid.org/0000-0003-2416-1186

References
1. Ali A, Lindstrand A, Sundberg M, Flivik G. Preoperative
anxiety and depression correlate with dissatisfaction after
total knee arthroplasty: a prospective longitudinal cohort
study of 186 patients, with 4-year follow-up. J Arthroplasty.
2017;32(3):767-770.
2. Anderson MR, Baumhauer JF, DiGiovanni BF, et al.
Determining success or failure after foot and ankle surgery
using Patient Acceptable Symptom State (PASS) and Patient
Reported Outcome Information System (PROMIS). Foot
Ankle Int. 2018;39(8):894-902.
3. Ayers DC, Franklin PD, Trief PM, Ploutz-Snyder R, Freund
D. Psychological attributes of preoperative total joint replacement patients: implications for optimal physical outcome. J
Arthroplasty. 2004;19(7)(suppl 2):125-130.

https://www.orcid.org/0000-0003-2416-1186

Foot & Ankle International - September 2019

Table of Contents for the Digital Edition of Foot & Ankle International - September 2019