The classes of evidence (I-IV) and the ratings of recommendations (A-C) are listed at the end of the "Major Recommendations" field.
- Prednisone has been demonstrated to have a beneficial effect on muscle strength and function in boys with Duchenne dystrophy (DD) and should be offered (at a dose of 0.75 mg/kg/day) as treatment (Level A). Maintaining a dosage of 0.75 mg/kg/day is optimal, but if side effects require a decrease in prednisone, a gradual tapering of prednisone (as indicated below) to dosages as low as 0.3 mg/kg/day will give less robust but significant improvement.
- Benefits and side effects of corticosteroid therapy need to be monitored. Timed function tests, pulmonary function tests, and age at loss of independent ambulation are useful to assess benefits. An offer of treatment with corticosteroids should include a balanced discussion of potential risks. Potential side effects of corticosteroid therapy (weight gain, cushingoid appearance, cataracts, short stature [i.e., a decrease in linear growth], acne, excessive hair growth, gastrointestinal symptoms, and behavioral changes) also need to be assessed. If excessive weight gain occurs (>20% over estimated normal weight for height over a 12-month period), based on available data, it is recommended that the dosage of prednisone be decreased (to 0.5 mg/kg/day with a further decrease after three to four months to 0.3 mg/kg/day if excessive weight gain continues) (Level A).
- Deflazacort (0.9 mg/kg/day) can also be used for the treatment of DD in countries in which it is available (Level A). Patients should be monitored for asymptomatic cataracts as well as weight gain during treatment with deflazacort.
Definitions:
Evidence Classification Scheme for Therapeutics
Class I: Evidence provided by a prospective, randomized, controlled clinical trial with masked outcome assessment, in a representative population. The following are required:
- Primary outcome(s) is/are clearly defined.
- Exclusion/inclusion criteria are clearly defined.
- Adequate accounting for drop-outs and crossovers with numbers sufficiently low to have minimal potential for bias.
- Relevant baseline characteristics are presented and substantially equivalent among treatment groups or there is appropriate statistical adjustment for differences.
Class II: Evidence provided by a prospective matched group cohort study in a representative population with masked outcome assessment that meets a-d above OR a randomized control trial in a representative population that lacks one criteria a-d
Class III: All other controlled trials (including well-defined natural history controls or patients serving as own controls) in a representative population, where outcome assessment is independent of patient treatment
Class IV: Evidence from uncontrolled studies, case series, case reports, or expert opinion
Translation of Evidence to Recommendations
Level A rating requires at least one convincing class I study or at least two consistent, convincing class II studies.
Level B rating requires at least one convincing class II study or at least three consistent class III studies.
Level C rating requires at least two convincing and consistent class III studies.
Rating of Recommendations
A = Established as effective, ineffective, or harmful for the given condition in the specified population
B = Probably effective, ineffective, or harmful (or probably useful/predictive or not useful/predictive) for the given condition in the specified population
C = Possibly effective, ineffective, or harmful (or possibly useful/predictive or not useful/predictive) for the given condition in the specified population
U = Data inadequate or conflicting; given current knowledge, treatment is unproven