Brigham and Women's Carpal Tunnel Questionnaire

Objective

The purpose of the test: In 1993, Levine et al developed The Brigham and Women’s Hospital Symptom Severity Scale (SSS) and Functional Status Scale (FSS) to measure symptom severity and functional status in patients with carpal tunnel syndrome (CTS)[1].

Intended Population

Interactive hand - carpel tunnel - L16F1.jpg

Levine et al[1]

  • Purpose of this study: development of the SSS and FSS and to assess reliability, validity, and responsiveness to clinical change
  • 77 pts with CTS were included in this study, 39 evaluated pre-op and 1 yr post op carpal tunnel release (CTR), 28 were managed non-op
  • 17 men, 50 women, 9 pt’s receiving workman’s compensation
  • median age 57
  • median duration of symptoms: 18 mo


Amadio et al[2]

  • Purpose of this study: to compare SSS and FSS responsiveness to clinical change to the following generic questionnaires: the DASH, AIMS2, and the SF-36 and to clinical examination findings and electrophysiological testing
  • 22 pt with CTS, evaluated 1 day prior and 3 mo post op CTR
  • all patients had failed non-op therapy
  • mean age 60


Katz et al [3]

  • Purpose of this study: to compare reliability, validity, and responsiveness of SSS and FSS in recipients and non-recipients of worker’s compensation
  • 268 pts, 155 work comp, SSS and FSS were measured pre op CTR and 6 months post op CTR
  • 197 women, 71 men
  • mean age: 40
  • mean symptom duration: work comp 2.2 mo, non work comp 5.6 mo


Ozyurekoglu et al[4]

  • Purpose of this study: to calculate the MCID of the SSS in patients with CTS
  • 28 pts included, results from SSS were analyzed prior to a carpal tunnel injection and 3 mo after a carpal tunnel injection
  • 19 women, 9 men, no workmen’s compensation claims
  • mean age: 38
  • inclusion criteria: c/o intermittent hand numbness and waking at night due to numbness, no previous treatment of CTS


Method of Use

Constructs or items the test was designed to measure: The SSS and FSS are self-administered questionnaires that were designed to measure symptom severity and functional status in patients with CTS.[1] The SSS consist of 11 questions based on six domains thought to be critical by experts for evaluating CTS: pain, paresthesia, numbness, weakness, nocturnal symptoms, and over all functional status. The FSS contains 8 functional activities that are commonly affected by CTS and that are performed by a wide variety of patients.[1]

Evidence

Reliability

Levine et al[1]: Test- retest reliability: researchers measured scores on the SSS and FSS 2 days apart and calculated pearson correlation coefficients: SSS was 0.91 FSS was 0.93 (excellent)
Internal consistency: SSS Chronbach alpha 0.89, FSS Chronbach alpha 0.91

Katz et al[3]: Internal consistency: SSS Chronbach alpha for the non work comp group was 0.89, work comp group 0.89
FSS Chronbach alpha for the non work comp group was 0.88, work comp group 0.89

Validity

Levine et al stated “there is no universally accepted measurement of the severity of symptoms or functional status of the hand.[1]” Therefore, they examined validity by assessing traditional objective measures of disability and impairment found in patients with CTS: grip, pinch strength, median nerve sensory conduction, 2 pt discrimination, and Semmes Weinstein monofilament testing. However, as expected they found mod-weak correlations because the SSS and FSS measure disability not usually captured by objective findings. Since objective findings in patients with CTS often do not correlate with symptom and functional improvements, these researchers also analyzed validity by looking at patient satisfaction. Greater satisfaction with results correlated with greater improvement in the SSS and FSS scores.[1]

Spearman Coefficients from Levine et al [1]:
Grip strength Pinch Strength 2 pt discrimination Semmes Weinstein

Pt. Satisfaction

(patients in the

retrospective cohort)

Pt. Satisfaction

(patients in the

prospective cohort)

SSS 0.38 (p<0.05) 0.47 (p<0.01) 0.15 0.17 0.52 (p=0.0007) 0.50 (p<0.01)
FSS 0.50 (p<0.001) 0.60 (p<0.001) 0.42 (p<0.01) 0.24 0.29 (p=0.09) 0.54 (p<0.01)

Amadio et al evaluated patients pre op and post op CTR and measured the following objective findings: sensation, grip strength, pinch strength, dexterity, and motion.[2] Their results found the only objective finding improved after a CTR was dexterity. No other physical measurement improved despite significant improvements on the SSS and FSS.[2] These findings support claims made by Levine et al that establishing validity of the SSS and FSS cannot be solely based on objective findings since improvements in symptoms and function do not always correlate with a change in objective findings.

Katz et al assessed validity by looking at patient satisfaction, perceived improvement in quality of life and perceived improvement in symptoms.[3] The following Spearman Coefficients were reported by Katz et al[3]:

Patient satisfaction Perceived improvement in quality of life perceived improvement in symptoms
WC NWC WC NWC WC NWC
SSS 0.69 0.37 0.68 0.37 0.59 0.31
FSS    0.55 0.21 0.54 0.41 0.48 0.19

WC- patients receiving workman’s compensation, NWC patients not receiving workman’s compensation

Responsiveness

Carpal Tunnel Syndrome.png

Levine et al[1]

  • Patient satisfaction post op CTR was highly correlated with improvements in the SSS and mod correlated with an improvement in the FSS
  • 38 pts evaluated retrospectively mean SSS pre-op was 3.4 and 1.9 post op, effect size 1.4; mean FSS 3.0 pre op and 2.0 post op, effect size 0.82
  • 28 pts evaluated prospectively mean SSS pre-op was 3.1 and 2.0 post op, effect size 1.13; Mean FSS 32.7 pre op and 2.1 post op, effect size 0.71


Amadio et al[2]

  • The SSS and FSS both showed a significant change p<0.01 in the direction of improved health status from pre-op to post-op
  • The SSS and FSS were found to be more responsive to clinical change than all clinical examination findings including electrophysiological testing and the DASH, AIMS2 and the SF-36


Minimal Clinical Important Difference (MCID)

The MCID is the smallest amount of change between two outcome measure scores that has clinical meaning to a patient. Ozyurekoglu et al determined the MCID of the SSS by using a ROC curve and analyzing the relationship between change scores on the SSS and the clinical result of a carpal tunnel injection. The clinical result of each injection was judged as satisfactory if the patient was satisfied with their results and did not require any additional care.[4]

The MCID of the SSS was determined to be 1.04 in this study. For practical purposes, the researchers suggest using 1.0 as the MCID.[4]

The MCID of the FSS has not been determined.

Suggestions for Use in the Clinic

The SSS and FSS scales can be used to monitor symptom severity and functional status in patients with CTS. Studies have shown that the objective findings in patients with CTS do not always correlate with improvements in symptoms and function, therefore the SSS and FSS can be very valuable tools for assessing a patient’s responsiveness to carpal tunnel interventions.[1][2] Currently, there is no research that has been conducted on the MCD but the MCID has been found to be 1.0.4 The SSS and FSS have been found to be reliable and valid in patients with CTS treated non-operatively and post-operatively.[1][3] The SSS and FSS have also been included as part of a clinical prediction rule for diagnosis of carpal tunnel syndrome.[5]

Links

Levine DM, Simmons BP, Koris MJ, Daltroy LH, Hohl GG, Fossel AH, Katz JN. A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am. 1993; 75: 1585-1592. http://www.ejbjs.org/cgi/reprint/75/11/1585

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Levine DM, Simmons BP, Koris MJ, Daltroy LH, Hohl GG, Fossel AH, Katz JN. A self-administered questionnaire for the assessment of severity of symptoms and functional status in carpal tunnel syndrome. J Bone Joint Surg Am. 1993; 75: 1585-1592
  2. 2.0 2.1 2.2 2.3 2.4 Amadio PC, Silverstein MD, Ilstrup DM, Schleck BS, Jensen LM. Outcome Assessment for Carpal Tunnel Surgery: The Relative Responsiveness of Generic, Arthritis-Specific, Disease-Specific, and Physical Examination Measures. JHand Surg (Am). 1996; 21A: 338-346.
  3. 3.0 3.1 3.2 3.3 3.4 Katz JN, Punnett L, Simmons BP, Fossel AH, Mooney N, Keller RB. Worker’s Compensation Recipients with Carpal Tunnel Syndrome: The Validity of Self-Reported Health Measures. Am J Public Health. 1996; 86(1): 52-56
  4. 4.0 4.1 4.2 Ozyurekoglu T, McCabe S, Goldsmith LJ, LaJoie AS. The Minimally Clinically Important Difference of the Carpal Tunnel Syndrome Symptom Severity Scale. J Hand Surg (Am). 2006; 31(5): 733-738.
  5. Wainner RS, Fritz JM, Irrgang JJ, Delitto A, Allison S, Bonninger M. Development of a Clinical Prediction Rule for the Diagnosis of Carpal Tunnel Syndrome. Arch Phys Med Rehab. 2005; 86(4): 609-618