Definitions for the levels of evidence (I–IV) can be found at the end of the "Major Recommendations" field.
Guidelines
No recommendations possible based on Level I or II evidence
Suggestions for Clinical Care
(Suggestions are based on Level III and IV sources)
- Smoking accelerates the development and progression of diabetic nephropathy. (Level III evidence - large retrospective cohort studies; clinically relevant outcomes; consistent strong effects)
- Cessation of smoking retards progression of diabetic nephropathy. (Level III evidence - small volume, several small cohort studies; clinically relevant outcomes; consistent strong effects)
- Current smoking confers a greater risk than former smoking.
- All patients with Type 1 or Type 2 diabetes should be strongly advised against commencement/continuation of smoking, to reduce the risk of developing and accelerating diabetic nephropathy as well as for vascular health.
Definitions:
Levels of Evidence
Level I: Evidence obtained from a systematic review of all relevant randomized controlled trials (RCTs)
Level II: Evidence obtained from at least one properly designed RCT
Level III: Evidence obtained from well-designed pseudo-randomized controlled trials (alternate allocation or some other method); comparative studies with concurrent controls and allocation not randomized, cohort studies, case-control studies, interrupted time series with a control group; comparative studies with historical control, two or more single arm studies, interrupted time series without a parallel control group
Level IV: Evidence obtained from case series, either post-test or pretest/post-test
