Kruger 1992.

Methods	RCT
Participants	50 people with diabetes mellitus randomised: intervention 23 vs control 27 Baseline risk for foot ulceration: no data provided Study setting: secondary outpatient care in the USA Inclusion criteria: diabetes duration at least 5 years (unclear which type of diabetes), no frank pathology, entering weekly hospital diabetes programme
Interventions	Intervention group: 1‐week patient education session. Content: education and guidance (unclear by whom) to assist people in achieving higher levels of general diabetes control Instructional videotape with supplementary explanation from an instructor. Content: usual teaching on foot care Additional hands‐on learning sessions during the same week. Content: actual foot washing, inspection, assessment, demonstration of care of corns and callus, toenail cutting, identification of potential foot problems, evaluation foot care Patient education kit. Content: buff pads and mirror Daily foot check sheets. Content: encouragement to perform daily foot inspection Control group: 1‐week patient education session. Content: education and guidance (unclear by whom) to assist people in achieving higher levels of general diabetes control Instructional videotape with supplementary explanation from an instructor. Content: usual teaching on foot care Daily foot check sheets. Content: encouragement to daily foot inspection Adherence: no data provided
Outcomes	Primary outcomes: none reported Secondary outcomes: foot status, foot care knowledge scores, behaviour assessment
Duration and completion of follow‐up	6 months; 30 people completed follow‐up: intervention 15 vs control 15
Types of assessment	Foot status assessment: 67 items Foot care knowledge assessment: 12‐item test Behaviour assessment: daily foot check sheets
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	People were allocated to intervention or control on the basis of the week that they entered the diabetes program. The experimental intervention group was developed similarly from the control group on alternate weeks Quote: "A random selection process determined whether the control or the experimental [intervention] group would begin the study"
Allocation concealment (selection bias)	High risk	Alternation is not an adequate method of allocation concealment
Blinding (performance bias and detection bias) Blinding of outcome assessors	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	High risk	30 of 50 people completed 6 months' follow‐up (intervention 15 vs control 15). Reasons for dropping out were death (n = 2), not wanting to make an appointment at the scheduled time and moving without leaving a forwarding address (numbers not reported) No ITT analyses were undertaken
Selective reporting (reporting bias)	Low risk	Yes. No study protocol available, but the trial report lists the outcomes of interest in both the methods and the results section
Other bias	Unclear risk	Baseline risk for foot ulceration: no data provided Co‐interventions were not described Adherence: no data provided