Lehmann et al categorized a clinical trials by identifying its strengths and weaknesses. The authors are from the Johns Hopkins University.
Parameters:
(1) those that are either strength or weakness
(2) those that are a strength
(3) those that are a weakness
|
Feature |
Strength |
Weakness |
|
assignment |
randomized |
deterministic |
|
patients |
blinded |
not blinded |
|
enroller |
blinded |
not blinded |
|
losses to followup |
nothing major |
major |
|
outcome assessor |
blinded |
not blinded |
Strengths:
(1) trial results generalizable
Weaknesses:
(1) inconsistent ascertainment of outcomes across arms
(2) patients in treatment arms not comparable
(3) trial execution did not follow the design
total number of strengths =
= SUM(number of strengths)
total number of weaknesses =
= SUM(number or weaknesses)
|
Strengths |
Weaknesses |
Trial Quality |
|
>= 1 |
0 |
high quality |
|
0 |
>= 1 |
low quality |
|
>= 1 |
>= 1 |
mixed quality |
|
0 |
0 |
indeterminate quality |
|
uncertain |
uncertain |
uncertain |
