Statements considering intervention effects in Finnish clinical practice guidelines: Recommending interventions with non-numeric effect-sizes or unspecified outcomes.

Rationale, Aims And Objectives: Representation of benefits and harms associated with specific interventions in an understandable and comparable way is crucial for informed decision making that clinical practice guidelines (CPGs) aim to enhance. Therefore, we investigated how statements concerning the effects of interventions considered and described benefits and harms, magnitude of effect and its uncertainty, numeric and non-numeric information, and outcomes in Finnish CPGs.

Methods: We selected 10 CPGs on common diseases and risk factors published by The Finnish Medical Society, Duodecim. All the statements which were graded with the level of evidence from high to very low (levels A-D) were included in analyses. From these statements, assessments were made regarding whether the statement considered benefits or harms, whether relative or absolute numeric measures were shown, whether the statement supported or was against the intervention considered, and what outcome was reported.

Results: Of the 10 CPGs, 448 statements were assessed. Most of the statements of effects considered intervention benefits (87%) rather than harms. Half of the statements considering harms were represented in a way that supported the intervention. Most of the statements (94%) did not include numeric estimates of magnitude of the effect. When numeric estimates of magnitude of the effect were present, they were most frequently relative measures and were typically placed in a statement considering (a) intervention benefits with a primary outcome, (b) given the grade of A for level of evidence, and (c) that supported the use of intervention.

Conclusions: In the Finnish CPGs, the statements were rarely framed with both absolute and relative numeric measures of an intervention's effect. Harms were rarely reported with a grade indicating the level of evidence. The users of CPGs would benefit from more consistent and understandable framing of statements considering both benefits and harms of interventions.