1529. Correlation between ODI, PROMIS and SF-12 in Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF)

Authors: Avani Vaishnav; Steven McAnany, MD; Catherine Gang, MPH; Sravisht Iyer, MD; Todd Albert, MD; Sheeraz Qureshi, MD, MBA (New York, NY)

Introduction:
As the focus in spine surgery shifts from radiographic to patient-centric outcomes, patient-reported outcomes measures(PROMs) are becoming important. Thus, it is vital to evaluate new outcome measures.

Objective:
To evaluate the correlation between Oswestry Disability Index(ODI), PROMIS Physical Function(PROMIS-PF) and Short Form-12 Physical Health Score(SF-12 PHS) in patients undergoing minimally invasive transforaminal lumbar interbody fusion(MI-TLIF).

Methods:
PROMs collected pre-operatively and 6-weeks, 3-months and 6-months post-operatively were analyzed using Pearson product-moment correlation.

Results:

Sixty-one patients were included. ODI decreased from 38.85+21.47 pre-operatively to 18.19+14.84 at 6-months. Similarly, PROMIS-PF and SF-12 PHS improved from 36.04+9.38 to 45.93+7.06 and 33.84+10.46 to 40.83+10.07, respectively at 6-months.

A statistically significant strong negative correlation was seen between ODI and PROMIS at all time points (Pre-operatively: r=-0.631,n=52,p<0.0001; 6-week: r=-0.640,n=41,p<0.0001; 3-month: r=-0.714,n=27,p<0.0001; 6-month: r=-0.744,n=9,p=0.021).

Similarly, a statistically significant negative correlation was seen between ODI and SF-12 PHS at all post-operative time-points, which was moderate at 6-weeks(r=-0.543,n=49,p<0.0001), strong at 3-months(r=-0.669,n=40,p<0.0001) and very strong at 6-months(r=-0.832,n=20,p<0.0001). Pre-operatively, the correlation was very weak and statistically non-significant(r=-0.086,n=58,p=0.522).

A statistically significant positive correlation was seen between SF-12 PHS and PROMIS at all post-operative time-points, which was moderate at 6-weeks(r=0.414,n=40,p=0.008), strong at 3-months(r=0.744,n=25,p<0.0001) and very strong at 6-months(r=0.870,n=8,p=0.005). Pre-operatively, the correlation was weak and statistically non-significant(r=-0.267,n=52,p=0.055).

Conclusion

While ODI has been used in lumbar spine patients for several years, PROMIS is a relatively new outcome measure that is increasingly being implemented. The results of our study show a statistically significant strong correlation between ODI and PROMIS at all time-points. In contrast, the correlation between ODI and SF-12, and SF-12 and PROMIS was statistically significant only in the post-operative period, ranging from moderate at 6 weeks to very strong at 6 months.

Thus, PROMIS-PF is a good surrogate for ODI at all time-points and a good surrogate for SF-12 >3 months follow-up.