MMT was scored using the 6-point Medical Research Council (MRC) scale [10 ]. Strength was evaluated bilaterally for 6 upper- and 7 lower-extremity muscle groups (total of 26 groups).
MRC scores for the 26 muscle groups were summed to yield a composite score of overall strength (range 0–130), as done previously [3 (link), 9 (link), 14 (link)]. Composite scores were also separately calculated for the upper (0–60) and lower extremities (0–70). Finally, an abbreviated composite score (0–60) was calculated based on a subset of 3 upper and 3 lower muscle groups, for comparison with a prior landmark study [9 (link)]. Composite scores were also dichotomized to designate patients with “clinically significant muscle weakness” if their score was <80% of the maximum score (i.e. average MRC score of <4 of 5 in all muscle groups) [3 (link), 4 (link), 9 (link), 14 (link)].
All personnel performing MMT completed multi-step training prior to their reliability assessments, including: review of a photo-illustrated MMT instruction manual; didactic teaching; and supervised practice by a trained staff member. The sole reference rater (NDC) was a physiotherapist with >30 years experience in both teaching and performing MMT across both clinical and research settings, particularly for ICU patients.
Nineteen different trainees underwent single-blinded MMT reliability evaluations with the reference rater. The trainees had various professional backgrounds (range of relevant experience with MMT): five physicians (1–10 years), four nurses (none), two respiratory therapists (none), five physiotherapists (6 months–5 years), one pharmacist (none), and two research assistants (none). Evaluations were conducted in a clinic setting using either an actual research participant (9 of 19) or a simulated patient (10 of 19) who effectively simulated a wide range of strength following training by the reference rater.
MRC scores for the 26 muscle groups were summed to yield a composite score of overall strength (range 0–130), as done previously [3 (link), 9 (link), 14 (link)]. Composite scores were also separately calculated for the upper (0–60) and lower extremities (0–70). Finally, an abbreviated composite score (0–60) was calculated based on a subset of 3 upper and 3 lower muscle groups, for comparison with a prior landmark study [9 (link)]. Composite scores were also dichotomized to designate patients with “clinically significant muscle weakness” if their score was <80% of the maximum score (i.e. average MRC score of <4 of 5 in all muscle groups) [3 (link), 4 (link), 9 (link), 14 (link)].
All personnel performing MMT completed multi-step training prior to their reliability assessments, including: review of a photo-illustrated MMT instruction manual; didactic teaching; and supervised practice by a trained staff member. The sole reference rater (NDC) was a physiotherapist with >30 years experience in both teaching and performing MMT across both clinical and research settings, particularly for ICU patients.
Nineteen different trainees underwent single-blinded MMT reliability evaluations with the reference rater. The trainees had various professional backgrounds (range of relevant experience with MMT): five physicians (1–10 years), four nurses (none), two respiratory therapists (none), five physiotherapists (6 months–5 years), one pharmacist (none), and two research assistants (none). Evaluations were conducted in a clinic setting using either an actual research participant (9 of 19) or a simulated patient (10 of 19) who effectively simulated a wide range of strength following training by the reference rater.
