Inter-examiner reliability of diplomats in the mechanical diagnosis and therapy system in assessing patients with shoulder pain.

OBJECTIVE: To investigate the inter-examiner reliability of Mechanical Diagnosis and Therapy (MDT)-trained diplomats in classifying patients with shoulder disorders. The MDT system has demonstrated acceptable reliability when used in patients with spinal disorders; however, little is known about its utility when used for appendicular conditions. METHODS: Fifty-four clinical scenarios were created by a group of 11 MDT diploma holders based on their clinical experience with patients with shoulder pain. The vignettes were made anonymous, and their clinical diagnoses sections were left blank. The vignettes were sent to a second group of six international McKenzie Institute diploma holders who were asked to classify each vignette according to the MDT categories for upper extremity. Inter-examiner agreement was evaluated with kappa statistics. RESULTS: There was 'very good' agreement among the six MDT diplomats for classifying the McKenzie syndromes in patients with shoulder pain (kappa = 0.90, SE = 0.018). The raw overall level of multi-rater agreement among the six clinicians in classifying the vignettes was 96%. After accounting for the actual MDT category for each vignette, kappa and the raw overall level of agreement decreased negligibly (0.89 and 95%, respectively). DISCUSSION: Using clinical vignettes, the McKenzie system of MDT has very good reliability in classifying patients with shoulder pain. As an alternative, future reliability studies could use real patients instead of written vignettes.

The 6-min walk test: responses in healthy Canadians aged 45 to 85 years.

We sought to describe responses to the 6-min walk test (6MWT) in healthy Canadian adults in order to facilitate interpretation of its results in patient populations. Seventy-seven healthy Canadians aged 45 to 85 years (65 ± 11 years, 40 females) completed this study. During a single visit, three 6MWTs were undertaken. The main outcome measure was 6-min walk distance (6MWD). Age, gender, height, and weight were recorded. In 61 (79%) participants, cardiorespiratory variables were collected during the third 6MWT using a calibrated portable gas analysis system. The 6MWD increased between the first and second test (615 ± 96 to 639 ± 98 m; p < 0.001) with no further improvement on the third test (638 ± 99 m; p = 0.945). The best 6MWD from the first 2 tests was 640 ± 99 m (range 416 to 880 m). A greater 6MWD was achieved by males compared with females (672 ± 94 vs. 611 ± 93 m; p = 0.005). The following equation accounted for 49% of the variance in 6MWD: 6MWD = 970.7 + (-5.5 × age) + (56.3 × gender), where females = 0, males = 1. The 6MWT elicited large cardiorespiratory responses with minimal symptoms. The rate of oxygen uptake measured at test-end was associated with the 6MWD (r = 0.802; p < 0.001). These data allow the 6MWD achieved in Canadian adults to be expressed as a percentage of the predicted value and provide researchers and clinicians with values for the expected cardiorespiratory responses in a healthy adult population for the purpose of comparison with patient populations.