====== Short Form-12 Physical Health Score ======
 

As the focus in [[spine surgery]] has shifted from radiographic to patient-centric [[outcome]]s, [[patient reported outcomes measures]] ([[PROMs]]) are becoming increasingly important. They are linked to patient [[satisfaction]], and are used to assess healthcare [[expenditure]], determine [[compensation]] and evaluate [[cost effectiveness]]. Thus, PROMs are important to various [[stakeholder]]s, including [[patient]]s, [[physician]]s, [[payer]]s and healthcare [[institution]]s. Thus, it is vital to establish methods to interpret and evaluate these [[outcome measure]]s.

To evaluate the correlation between [[Neck Disability Index]] (NDI), [[Patient Reported Outcome Measurement Information System Physical Function]] (PROMIS-PF) and [[Short Form-12 Physical Health Score]] (SF-12 PHS) in [[cervical spine surgery]] in order to determine the validity of [[PROMIS-PF]] in these patients.

Retrospective review of prospectively collected data PATIENT SAMPLE: Consecutive patients who underwent cervical surgery for degenerative spinal pathology with a minimum of 3 months follow-up OUTCOME MEASURES: Self-reported measures i.e. PROMs, including NDI, PROMIS-PF and SF-12 PHS METHODS: No funding was received for this study. The authors report no relevant conflict of interest. PROM collected pre-operatively and at each follow-up were analyzed using Pearson product-moment correlation.

Of the 121 patients included, 66 underwent [[ACDF]], 42 [[cervical]] [[disc replacement]], 13 [[posterior cervical decompression]] with or without [[fusion]]. A statistically significant improvement was achieved in all PROMs by 6 weeks and maintained at 1 year. Furthermore, the percentage of patients achieving an improvement greater than MCID was similar for NDI and PROMIS-PF, particularly at a follow-up of 3 months or more. A statistically significant negative correlation was seen between [[NDI]] and PROMIS-PF, which was moderate pre-operatively and in the early post-operative period (r= - 0.565 to -0.600), and strong at 3 months or longer follow-up (r=-0.622 to -0.705). A statistically significant, negative correlation was also seen between [[SF-12 PHS]] and NDI, which was moderate pre-operatively and at 6 weeks (r=-0.5551 to -0.566); and strong at all other time-points (r=-0.678 to -0.749). There was a statistically significant positive correlation between SF-12 PHS and [[PROMIS-PF]], which was strong to very-strong at all time-points (r=0.644 to 0.822), except at 2 weeks (r=0.570).

While [[NDI]] and [[SF-12]] have been used for several years, [[PROMIS]] is a new outcome measure that is increasingly being implemented. The results of this study demonstrate the convergent and discriminant validity of [[PROMIS-PF]], supported by the strong correlation between [[SF-12 PHS]] and [[PROMIS-PF]] at all time-points and the moderate correlation between NDI and PROMIS-PF pre-operatively and in the early post-operative period, respectively. Thus, while PROMIS-PF may not be a good surrogate for disease-specific outcome measures, it may extend value as a precise and efficient general health tool
((Vaishnav AS, Gang CH, Iyer S, McAnany S, Albert T, Qureshi SA. Correlation
between NDI, PROMIS and SF-12 in Cervical Spine Surgery. Spine J. 2019 Oct 31.
pii: S1529-9430(19)31063-0. doi: 10.1016/j.spinee.2019.10.017. [Epub ahead of
print] PubMed PMID: 31678044.
)).
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Regression methods were used to select and score 12 items from the Medical Outcomes Study 36-Item Short-Form Health Survey ([[SF-36]]) to reproduce the Physical Component Summary and Mental Component Summary scales in the general US population (n=2,333). The resulting 12-item short-form (SF-12) achieved multiple R squares of 0.911 and 0.918 in predictions of the SF-36 Physical Component Summary and SF-36 Mental Component Summary scores, respectively. Scoring algorithms from the general population used to score 12-item versions of the two components (Physical Components Summary and Mental Component Summary) achieved R squares of 0.905 with the SF-36 Physical Component Summary and 0.938 with SF-36 Mental Component Summary when cross-validated in the Medical Outcomes Study. Test-retest (2-week)correlations of 0.89 and 0.76 were observed for the 12-item Physical Component Summary and the 12-item Mental Component Summary, respectively, in the general US population (n=232). Twenty cross-sectional and longitudinal tests of empirical validity previously published for the 36-item short-form scales and summary measures were replicated for the 12-item Physical Component Summary and the 12-item Mental Component Summary, including comparisons between patient groups known to differ or to change in terms of the presence and seriousness of physical and mental conditions, acute symptoms, age and aging, self-reported 1-year changes in health, and recovery for depression. In 14 validity tests involving physical criteria, relative validity estimates for the 12-item Physical Component Summary ranged from 0.43 to 0.93 (median=0.67) in comparison with the best 36-item short-form scale. Relative validity estimates for the 12-item Mental Component Summary in 6 tests involving mental criteria ranged from 0.60 to 107 (median=0.97) in relation to the best 36-item short-form scale. Average scores for the 2 summary measures, and those for most scales in the 8-scale profile based on the 12-item short-form, closely mirrored those for the 36-item short-form, although standard errors were nearly always larger for the 12-item short-form
((Ware J Jr, Kosinski M, Keller SD. A 12-Item Short-Form Health Survey:
construction of scales and preliminary tests of reliability and validity. Med
Care. 1996 Mar;34(3):220-33. PubMed PMID: 8628042.
)).