Skip to main content
. Author manuscript; available in PMC: 2015 May 1.
Published in final edited form as: JAMA. 2014 May;311(20):2092–2100. doi: 10.1001/jama.2014.4949

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.