Estimated risk of gestational diabetes in each study year, compared with 2005, in a population-based cohort from British Columbia, Canada (> 28 weeks’ gestation at delivery and without pre-existing diabetes)
| Year | Relative risk (95% CI)* | |||
|---|---|---|---|---|
| Model 1: Year | Model 2: Year and screening completion† | Model 3: Year, screening completion and screening method‡ | Model 4: Year, screening completion, screening method and population characteristics§ | |
| 2005 | Ref. | Ref. | Ref. | Ref. |
| 2006 | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) | 0.96 (0.91–1.01) |
| 2007 | 1.04 (0.99–1.10) | 1.04 (0.98–1.09) | 1.04 (0.98–1.09) | 1.04 (0.98–1.09) |
| 2008 | 1.06 (1.01–1.12) | 1.05 (1.00–1.11) | 1.05 (1.00–1.11) | 1.04 (0.99–1.09) |
| 2009 | 1.12 (1.06–1.17) | 1.10 (1.04–1.16) | 1.10 (1.04–1.16) | 1.09 (1.03–1.14) |
| 2010 | 1.05 (1.00–1.11) | 1.03 (0.98–1.09) | 1.03 (0.98–1.09) | 1.02 (0.97–1.07) |
| 2011 | 1.27 (1.21–1.34) | 1.25 (1.19–1.31) | 0.98 (0.93–1.03) | 1.02 (0.97–1.07) |
| 2012 | 1.44 (1.37–1.51) | 1.40 (1.33–1.47) | 0.91 (0.87–0.96) | 0.98 (0.93–1.03) |
| 2013 | 1.60 (1.52–1.67) | 1.55 (1.47–1.62) | 0.97 (0.92–1.02) | 1.04 (0.99–1.09) |
| 2014 | 1.51 (1.44–1.58) | 1.45 (1.38–1.52) | 0.96 (0.91–1.01) | 1.01 (0.96–1.06) |
| 2015 | 1.66 (1.58–1.74) | 1.58 (1.51–1.66) | 1.10 (1.05–1.16) | 1.13 (1.07–1.18) |
| 2016 | 1.74 (1.66–1.82) | 1.65 (1.57–1.73) | 1.15 (1.09–1.20) | 1.16 (1.11–1.22) |
| 2017 | 1.85 (1.77–1.94) | 1.74 (1.66–1.82) | 1.22 (1.17–1.28) | 1.19 (1.13–1.24) |
| 2018 | 1.85 (1.77–1.94) | 1.73 (1.65–1.81) | 1.23 (1.17–1.28) | 1.16 (1.11–1.22) |
| 2019 | 2.04 (1.94–2.13) | 1.89 (1.81–1.98) | 1.34 (1.28–1.40) | 1.25 (1.19–1.31) |
Note: CI = confidence interval, Ref. = reference.
↵* CIs assessed using robust standard errors.
↵† Screen completion was modelled as any screening for gestational diabetes versus unscreened or no data
↵‡ Screening method was modelled as any 2-step screening approach versus 1-step screening.
↵§ Population characteristics included parity (nulliparous v. multiparous), age at delivery of mother or birthing person (< 25, 25–34, ≥ 35 yr), pre-pregnancy body mass index (< 24.5, 25–29.9, > 30 kg/m2 or missing data), pre-existing complications (any of pre-existing hypertension, pregnancy-complicating conditions or diseases, previous stillbirth, previous neonatal death or congenital anomaly in a previous birth), multifetal pregnancy, antenatal midwife care (v. any other), inadequate prenatal care and region of birth of mother or birthing person (Asia v. Canada or United States v. all others).