|
Selection |
(1) Representativeness of the exposed cohort |
(a) truly representative of the average RA patient in the |
community* |
(b) somewhat representative of the average RA patient in the |
community* |
(c) selected group of users e.g., nurses, volunteers |
(d) no description of the derivation of the cohort |
(2) Selection of the nonexposed cohort |
(a) drawn from the same community as the exposed cohort* |
(b) drawn from a different source |
(c) no description of the derivation of the nonexposed cohort |
(3) Ascertainment of exposure |
(a) secure record (e.g., surgical records)* |
(b) structured interview * |
(c) written self-report |
(d) no description |
(4) Demonstration that outcome of interest was not present at start |
of study |
(a) yes* |
(b) no |
|
Comparability |
(1) Comparability of cohorts on the basis of the design or analysis |
(a) study controls for surgical time* |
(b) study controls for any additional factor * |
|
Outcome |
(1) Assessment of outcome |
(a) independent blind assessment* |
(b) record linkage* |
(c) self-report |
(d) no description |
(2) Was followup long enough for outcomes to occur? |
(a) yes (1 year) |
(b) no |
(3) Adequacy of followup of cohorts |
(a) complete follow up—all subjects accounted for* |
(b) subjects lost to followup unlikely to introduce bias—small |
number lost—>80% follow up, or description provided of those |
lost* |
(c) followup rate < 80% and no description of those lost |
(d) no statement |
|