Bassel G. Diebo, MD, FAAOSSpine and scoliosis surgeon
For clinicians

The SRS-22r Outcome Questionnaire

Short answer. The SRS-22r is a 22-item questionnaire from the Scoliosis Research Society. It measures function, pain, self-image, mental health, and satisfaction with treatment. Each item is scored from 1 (worst) to 5 (best), and each domain score is the average of its items. In adult deformity surgery, a change of about 0.4 points is commonly treated as clinically meaningful, with some important caveats.

What does the SRS-22r measure?

DomainItemsInternal consistency (Cronbach's α)
Function/activity50.83
Pain50.87
Self-image/appearance50.80
Mental health50.90
Satisfaction with management20.73

The subscore (or total) is usually calculated from the first four domains, without satisfaction. Population-based normative data exist for adolescents and adults. The SRS-22r is also part of the core outcome set for spinal deformity.

How is it scored?

Each domain score is the mean of the items answered, on a 1–5 scale. Ceiling effects of 20–44% have been reported, which limits sensitivity in patients who are only mildly affected.

What is a clinically meaningful change?

In 1,321 adults having deformity surgery, Crawford and colleagues (2015) concluded that the minimal clinically important difference (MCID) can be estimated at 0.4. That corresponds to a one-step change on two of the five items in a domain. Other reports give different values:

  • A systematic review: 0.43–0.94
  • A 2024 ROC-based analysis in operated adult deformity patients: 0.64

Values for adolescent idiopathic scoliosis differ substantially by domain.

Caveat: Kelly and colleagues (2018) found that the minimum detectable measurement difference exceeds 0.4 for the Pain domain (0.6) and the Self-Image domain (0.5). On those domains, a 0.4 change may fall within measurement noise. Detectable differences also vary with age and baseline disability.

How is the SRS-22r used in adult deformity research?

In the NIH-funded ASLS trial, surgery improved the SRS-22 score by 0.7 points more than non-operative care in the as-treated analysis. About 86% of operative patients reached the MCID, compared with about 39% of non-operative patients. Across deformity types, self-image is the most impaired domain before surgery and improves the most afterward. Patient satisfaction correlates more strongly with self-image improvement (r = 0.64) than with radiographic correction.

Where can I get the questionnaire?

The official SRS-22r forms, translations, and scoring instructions are hosted by the Scoliosis Research Society at srs.org/Research/Patient-Outcome-Questionnaires. Do not reproduce the questionnaire items on diebo.com. Link to SRS instead, and follow SRS terms for research use.

Using it in clinical care

Sources
  1. Crawford, C. H., et al. "The Minimum Clinically Important Difference in SRS-22R Total Score, Appearance, Activity and Pain Domains After Surgical Treatment of Adult Spinal Deformity." Spine, 2015. †
  2. Kelly, M. P., et al. "Minimum Detectable Measurement Difference for Health-Related Quality of Life Measures Varies With Age and Disability in Adult Spinal Deformity." Spine, 2018. †
  3. Lai, S. M., et al. "Identification of Scoliosis Research Society-22r Health-Related Quality of Life Questionnaire Domains Using Factor Analysis Methodology." Spine, 2010. †
  4. Kelly, Michael P., et al. "Operative Versus Nonoperative Treatment for Adult Symptomatic Lumbar Scoliosis." Journal of Bone and Joint Surgery (Am), 2019. †

← For clinicians