Incidence of lower extremity amputation in the diabetic compared to the non-diabetic population: a systematic review protocol

Table 1 Assessment of risk of bias (adapted to Cochrane approach Study Quality Guide [20])

Assessment items	Lower risk of bias	Higher risk of bias
Measurement and definition of outcomes LEA	Precise definition and description of how the LEA were recorded	No definition and description of how the LEA were recorded
Diagnostic criteria of diabetes	Documented by physician (clinical diagnosis, ICD)	Self-reported DM
Statistical methods: IR, CumI, RR	Presented as age-sex adjusted estimates; reported with CI	Crude rates; reported without CI
Time trends	Time trends reported using multivariate regression models	Time trends reported only descriptive
Duration of the observation period^a	5 years and more	Less than 5 years

CI confidence interval, CumI cumulative incidence, DM diabetes mellitus, ICD International Statistical Classification of Diseases and Related Health Problems, IR incidence rate, RR relative risk
^aRelevant for studies reporting time trend

ISSN: 2046-4053