Table 4.
Durability Class I ACC/AHA Guideline Recommendations With Differing Levels of Underlying Scientific Evidence Among 448 Index Recommendations for Which Level-of-Evidence Data Were Availablea
| Level of Evidence A: Multiple Randomized Clinical Trials or Meta-analyses |
Level of Evidence B: Single Randomized Trial or Nonrandomized Studies |
Level of Evidence C: Consensus Opinion, Case Studies, or Standard of Care |
|
|---|---|---|---|
| Status of recommendation in revised (current) guideline, No. (%)b | (n = 105) | (n = 195) | (n = 148) |
| Retained | 95 (90.5) | 158 (81.0) | 109 (73.7) |
| Downgraded or reversed | 4 (3.8) | 25 (12.8) | 14 (9.5) |
| Omitted | 6 (5.7) | 12 (6.2) | 25 (16.9) |
a
Level-of-evidence data were available for 448/619 (72.4%) index recommendations in our sample; no level-of-evidence data were provided for recommendations in the 1998 guideline on valvular heart disease or the 2002 guideline on perioperative evaluation and care.
b
Exact P value equals .001 for difference in percentages retained, downgraded/reversed, and omitted across levels of evidence.