Improving birth outcomes for women who are substance using or have mental illness: a Canadian cohort study comparing antenatal midwifery and physician models of care for women of low socioeconomic position

Table 4 Post-hoc power estimates for moderation analyses investigating antenatal models of care by small-for-gestational-age birth and pre-term birth (alpha set at 0.10)

Moderating Factor	MW vs. GP (%)	MW vs. OB (%)	GP vs. OB (%)
Small-for-Gestational-Age Birth
Mental illness	93.96	94.63	28.17
Substance use	72.05	83.46	29.69
Teen mother	6.43	19.80	47.04
Mental illness, substance use^a	–	–	18.25
Preterm Birth
Mental illness	48.79	99.97	99.95
Substance use	47.40	99.37	99.96
Teen mother	6.96	12.70	40.57
Social assistance	12.50	52.39	75.36
Neigh. SEP	96.77	100	100
Mental illness, substance use^a	–	–	95.83
Mental illness, social assistance	41.30	87.37	82.03
Substance use, social assistance^a	–	–	94.62

Abbreviations: MW midwife, GP general practitioner, OB obstetrician, Neigh neighbourhood
^aPercentage suppressed due to low frequency of cases

ISSN: 1471-2393