Summary of evidence table for nurse or midwife-led counselling intervention studies to assist pregnant smokers achieve abstinence
| Population: | Pregnant smokers | |||||
| Setting: | Any setting* | |||||
| Intervention: | Nurse or midwife led counselling† | |||||
| Comparison: | Usual care or control‡ | |||||
| Outcome | Anticipated absolute effects (95% CI) | Relative effect (95% CI)§ | No of participants (studies) | Certainty of evidence (Grading of Recommendations Assessment, Development and Evaluation) | Comments | |
| Effect with usual care or control group | Effect with intervention | |||||
| Nurse or midwife-led interventions | ||||||
| Nurse or midwife-led counselling interventions (biochemically validated) on point prevalence abstinence¶ in late pregnancy | 104 per 1000 | 155 per 1000 | 1.56 (1.16 to 2.06) | 1623,4 (15) | ⊕⊕⊕○** Moderate | Heterogeneity is increased to moderate to high and made significant by Everett-Murphy et al105 (ie, 61% p<0.01) |
| Nurse or midwife-led counselling interventions (biochemically validated) on point prevalence abstinence at postpartum (1–3 months, 4–6 months and 7–18 months) and unspecified) | 60 per 1000 | 146 per 1000 | 1.79 (1.14 to 2.83) | 5466 (13) | ⊕⊕○○†† Low | Heterogeneity is moderate and mostly impacted by one study104 |
| Nurse or midwife-led counselling interventions (biochemically validated) on continuous abstinence‡‡ in late pregnancy | 14 per 1000 | 29 per 1000 | 2.06 (0.90 to 4.71) | 918 (1) | See comment | Only one study (with two different measurements) could be included for this outcome |
| Nurse or midwife-led counselling interventions (biochemically validated) on continuous abstinence at postpartum (1–3 months, 4–6 months and 7–18 months and unspecified) | 132 per 1000 | 143 per 1000 | 1.43 (0.84 to 2.45) | 7646 (6) | ⊕⊕○○§§ Low | Heterogeneity is increased by 'undefined postpartum' and '1–3 months postpartum' measures |
*Included studies were conducted in a variety of countries (ie, low, middle or high income countries), included English and non-English speaking populations, and recruitment occured mainly through antenatal or maternity clinics and/or hospitals and community general/primary care practices. Included studies may have involved pregnant smokers of various socio-economic positions.
†Nurse or midwife-led counselling interventions included studies where nurses or midwives were or could be delivering the smoking cessation counselling intervention. Such interventions predominantly involved counselling or coaching as part of the antenatal or nursing/midwifery care services. The nurse or midwife-led counselling included brief or more comprehensive types counselling, including the 5As (ie, ask, advice, assess, assist and arrange), trans-theoretical model and cognitive behavioural herapy approaches and were measured alongside other interventions such as self-help or smoking cessation material, social support, follow-up, Digital Health, as part of a nurse visitation programme or a combination of those interventions.
‡Usual care often included no specific intervention, very brief smoking cessation counselling or advice, provision of printed or similar information.
§Relative effect was calculated as relative risk where risk is treated as effect rather than risk and CI is for this calculated relative effect.
¶Point prevalence abstinence was either defined as point prevalence abstinence of various time periods or was abstinence at a point in time that was biochemically validated but was not specifically defined. This type of abstinence did not include continuous abstinence which is understood as abstinence for a period of time rather than a point in time.
**Moderate certainty in evidence due to high risk of bias in 4 of the 15 studies and some concern in risk of bias to seven other studies, inconsistency due to significant moderate to high heterogeneity and low overlap of CIs. Certainty in evidence was upgraded due to a large effect size.
††Low certainty in evidence due to high risk of bias in 6 out of 12 studies and some concern in risk of bias in four other studies, imprecision due to large CIs as well as publication bias. Certainty in evidence was upgraded due to a large effect size.
‡‡Continuous abstinence was defined as abstinence for a period of time rather than at a time point. This definition included both undefined and defined time periods.
§§Low certainty in evidence due to high risk of bias in two studies and some concern in risk of bias in 3 out of the six included studies, inconsistency due to significant moderate heterogeneity and limited overlap in CI, imprecision caused by CI crossing value of 1 and publication bias. Certainty of evidence was upgraded due to large effect size.