The SF-6D health utility index in carpal tunnel syndrome

Cost effectiveness is an important factor to consider when choosing between various hand surgical interventions. Health utility measures can be used to determine cost effectiveness. The SF-6D is a health utility index derived from 11 items of the SF-36 quality of life questionnaire; values range from 0.296 to 1.0 ("perfect" health). We evaluated the validity of the SF-6D in patients with carpal tunnel syndrome (CTS) who completed the SF-36 and the CTS symptom severity and functional status questionnaire before and 3 months after carpal tunnel release. Complete responses to the SF-6D items were available for 100 patients at baseline and 95 patients at baseline and follow-up. The mean SF-6D health utility index was 0.69 (SD 0.13) before surgery and 0.77 (SD 0.13) after surgery (moderate effect size). The SF-6D could discriminate between patient groups differing in self-rated global health and in whether, or not, they had a minimal clinically important improvement in CTS symptom severity after surgery. The SF-6D appears to be a valid measure of health utilities in patients with CTS and can be used in cost effectiveness studies.

The disabilities of the arm, shoulder and hand (DASH) outcome questionnaire: reliability and validity of the Swedish version evaluated in 176 patients

The disabilities of the arm, shoulder and hand (DASH) questionnaire is a self-administered region-specific outcome instrument developed to measure upper-extremity disability and symptoms. The DASH consists mainly of a 30-item disability/symptom scale. We performed cross-cultural adaptation of the DASH to Swedish, using a process that included double forward and backward translations, expert and lay review, as well as field-testing to achieve linguistic and conceptual equivalence. The Swedish version's reliability and validity were then evaluated in 176 patients with upper-extremity conditions. The patients completed the DASH and SF-12 generic health questionnaire before elective surgery or physical therapy. Internal consistency of the DASH was high (Cronbach alpha 0.96). Test-retest reliability, evaluated in a subgroup of 67 patients who completed the DASH on two occasions, with a median interval of 7 days, was excellent (intraclass correlation coefficient 0.92). Construct validity was shown by a positive correlation of DASH scores with the SF-12 scores (worse upper-extremity disability correlating with worse general health), stronger correlation with the SF-12 physical than with the mental health component, correlation of worse DASH scores with worse self-rated global health, and ability to discriminate among conditions known to differ in severity. The Swedish version of the DASH is a reliable and valid instrument that can provide a standardized measure of patient-centered outcomes in upper-extremity musculoskeletal conditions.

Carpal tunnel syndrome with severe sensory deficit: endoscopic release in 18 cases

Carpal tunnel syndrome (CTS) with severe sensory deficit was treated with endoscopic carpal tunnel release in 18 hands of 16 consecutive patients (median age 72 (28-92) years). In all hands, preoperative 2-point discrimination (2-PD) exceeded 15 mm in the radial and ulnar sides of the pulps of at least 2 of the 3 radial digits. All patients underwent an independent evaluation and answered a questionnaire concerning 11 activities of daily living (ADL) preoperatively and 6 months postoperatively. Complete resolution or improvement in daytime numbness and tingling was reported in 12 of 17 hands, of night symptoms in 12 of 16 hands, and of pain in 10 of 11 hands. The median ADL score improved from 3.1 to 1.4 (on a 1- to 5-point scale). 13 of the 16 patients were satisfied with the outcome. Two-PD had normalized in 14 hands and improved in 2. The results indicate that endoscopic carpal tunnel release is effective in improving symptoms and function in patients with CTS and severe sensory deficit, and that the prognosis for sensory recovery is good.

[Prevalence for clinically proved carpal tunnel syndrome is 4 percent]

This article summarizes the results of a large-scale population-based study conducted to determine the prevalence of carpal tunnel syndrome in the Swedish general population. The study utilized a health questionnaires as well as clinical and electrophysiological examinations. Population prevalence rates of carpal tunnel syndrome, based on clinical diagnosis and electrophysiological criteria, were calculated. Obesity and specific work-related hand activities were shown to be risk factors for carpal tunnel syndrome.

Median nerve latency measurement agreement between portable and conventional methods

A portable nerve conduction testing device was compared with a conventional method of measuring median nerve distal latencies. In a population-based study, a health questionnaire was mailed to a random sample of 3000 participants (aged 25 to 74 years). Two hundred and sixty-two responders with numbness and/or tingling in the median nerve distribution, and 125 asymptomatic responders underwent clinical examination as well as portable and conventional median nerve distal latency measurements. Motor latency measured with the portable device was on average 0.1 millisecond (ms) lower than motor latency measured with the conventional method (95% limits of agreement, -0.8-0.5 ms). Sensory latency (wrist-to-index finger) measured with the portable device was on average 0.3 ms lower than sensory latency (long finger-to-wrist) measured with the conventional method (95% limits of agreement, -0.7-0.1 ms). Strong correlations were found between the latencies measured by the portable and conventional methods (Pearson correlation coefficient, 0.90-0.93). The agreement between the portable and conventional methods in measuring median nerve distal latencies appears to be acceptable. The cut-off value for abnormal sensory latency needs to be lower for the portable than the conventional method if the present measurement techniques are used.

Prevalence of carpal tunnel syndrome in a general population

CONTEXT

Carpal tunnel syndrome (CTS) is a cause of pain, numbness, and tingling in the hands and is an important cause of work disability. Although high prevalence rates of CTS in certain occupations have been reported, little is known about its prevalence in the general population.

OBJECTIVE

To estimate the prevalence of CTS in a general population.

DESIGN

General health mail survey sent in February 1997, inquiring about symptoms of pain, numbness, and tingling in any part of the body, followed 2 months later by clinical examination and nerve conduction testing of responders reporting symptoms in the median nerve distribution in the hands, as well as of a sample of those not reporting these symptoms (controls).

SETTING

A region in southern Sweden with a population of 170000.

PARTICIPANTS

A sex- and age-stratified sample of 3000 subjects (age range, 25-74 years) was randomly selected from the general population register and sent the survey, with a response rate of 83% (n = 2466; 46% men). Of the symptomatic responders, 81% underwent clinical examination.

MAIN OUTCOME MEASURES

Population prevalence rates, calculated as the number of symptomatic responders diagnosed on examination as having clinically certain CTS and/or electrophysiological median neuropathy divided by the total number of responders.

RESULTS

Of the 2466 responders, 354 reported pain, numbness, and/or tingling in the median nerve distribution in the hands (prevalence, 14.4%; 95% confidence interval [CI], 13.0%-15.8%). On clinical examination, 94 symptomatic subjects were diagnosed as having clinically certain CTS (prevalence, 3.8%; 95% CI, 3.1%-4.6%). Nerve conduction testing showed median neuropathy at the carpal tunnel in 120 symptomatic subjects (prevalence, 4.9%; 95% CI, 4.1%-5.8%). Sixty-six symptomatic subjects had clinically and electrophysiologically confirmed CTS (prevalence, 2.7%; 95% CI, 2.1%-3.4%). Of 125 control subjects clinically examined, electrophysiological median neuropathy was found in 23 (18.4%; 95% CI, 12.0%-26.3%).

CONCLUSION

Symptoms of pain, numbness, and tingling in the hands are common in the general population. Based on our data, 1 in 5 symptomatic subjects would be expected to have CTS based on clinical examination and electrophysiologic testing.

Symptoms, disability, and quality of life in patients with carpal tunnel syndrome

We used validated outcome instruments to measure symptoms, disability, and health-related quality of life in 58 patients with carpal tunnel syndrome (CTS). The patients completed the CTS instrument before and 6 weeks, 3 months, and 6 months after surgery and the Short Form-36 (SF-36) before and 3 months after surgery. The size of clinical change detected by each outcome measure was estimated by the standardized response mean (mean change/ standard deviation of the change). Large improvement was observed for the CTS symptom scale (mean standardized response, 1.4-1.9) and function scale (0.8-1.1). Improvement in SF-36 scales was large for pain (1.0) and moderate for physical role, mental health, and the physical component summary (0.5-0.6). Compared with the general population SF-36 norms (n = 2,181), CTS patients had significantly worse scores for physical functioning, physical role, pain, vitality, and the physical component summary before surgery. After surgery, SF-36 scores had normalized except for physical role and the physical component summary.