Adapted from the American College of Chest Physicians (ACCP) 2004 PH Guidelines and the recommendations from the 5th International symposium published in 2013.

Recommendations or clinical practice guidelines to physicians are based on the best information or evidence available at the time the recommendations are made. In order for physicians to understand how clear and strong the recommendation is, the strength of the evidence is assessed, and assigned a rating. The evidence is rated according to the type and size of available studies. The final recommendation is also assessed for its strength, and assigned a grade.

Quality of the evidence is rated as follows:

  • Good = evidence is based on 2 types of studies: (1) good randomized clinical trials which include a placebo or untreated control group, and (2) meta-analyses, which analyze a series of studies, and calculate an overall or average effect or benefit
  • Fair = evidence is based on studies with minor flaws, including randomized clinical trials or other trials with control groups
  • Low = evidence is based on studies which were not scientifically strong, because of lack of randomization of patients or simple observational studies
  • Expert opinion = evidence is based on the agreed opinion or consensus of a panel of PH experts, because there are no adequate studies that are useful

Strength of recommendation is graded as follows:

  • A = strong recommendation in favour of a treatment or intervention
  • B = moderate recommendation in favour of a treatment or intervention
  • C = weak recommendation in favour of a treatment or intervention
  • D = recommendation against a treatment or intervention
  • I = no recommendation is possible because of inconclusive information