Charron‐Prochownik 2013.

Methods	Randomised controlled trial
Participants	113 girls were randomised Setting: diabetes clinics at 2 university hospitals, USA; dates of recruitment not clear Inclusion criteria: adolescent girls between 13 and < 20 years with type 1 or type 2 diabetes for > 1 year Exclusion criteria: not described
Interventions	Intervention group (n = 51 had complete data): READY‐Girls In addition to routine care in the diabetes clinic, girls received the READY‐Girls programme over 3 consecutive visits attached to their routine visits. A trained research nurse/research associate prepared the computer in a private room for data collection and DVD programme viewing. At baseline, girls were given DVD‐1; they received boosters at 3 (DVD‐2) and 6 months (book). The first DVD sessions provided evidence‐based information (viewing time mean: 36.3 (6.2) minutes); the second DVD included exercises to apply information about preconception counselling from DVD‐1 (viewing time of 25.4 (7.4) minutes); in the third session the girls read a book that reinforced the information in DVD‐1 (reading time of 20.4 (4.0) minutes). Control group (n = 58 had complete data): girls received routine care in the diabetes clinic, including general preconception counselling March of Dimes pamphlets
Outcomes	Diabetes and reproductive health knowledge; attitudes/beliefs, behaviours related to family planning; initiation of preconception care and discussions with healthcare practitioners Data were collected by validated questionnaires at baseline, and each booster session (3 and 6 months) and 12‐month follow‐up
Notes	Funding: Supported by Grant R01‐HD‐044097 from the National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health and Human Development, the General Clinical Research Center of the Children’s Hospital of Pittsburgh (M01‐RR‐0084), the Pediatric Clinical and Translational Research Center (National Institutes of Health/National Center for Research Resources/Clinical and Translational Science Award UL1‐RR‐024153), and the National Institutes of Health/National Institute of Nursing Research/Center for Research in Chronic Disorders (P30‐NR‐03924) Declarations of interest: "No potential conflicts of interest relevant to this article were reported."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"randomized using a minimization algorithm."
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of participants and personnel not feasible
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of outcome assessors not specified. Data collection for some outcomes used self‐administered computer programme. It was not clear how lack of blinding would affect the outcome assessment
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	109/113 girls recruited had complete data; numbers randomised to each group not reported, nor the reasons for incomplete data. Attrition at 12 months was 16% (18/113)
Selective reporting (reporting bias)	Unclear risk	Data presented in text and in figures (e.g. means with no measure of variance). No access to trial registration/protocol to further assess whether all pre‐specified outcomes were reported as planned
Other bias	Unclear risk	Manuscript reports "no significant demographic differences between groups at baseline" (relatively small sample; difficult to determine group differences, i.e. ≥ 1 episode unprotected sex: 64% intervention group vs 36% control group)