Participants and setting
Depression
RECRUITMENT, DISEASES
A department in the City of Oslo selected and matched five city districts of Oslo as either intervention or control districts. The aim of matching the groups was to achieve equality between the intervention and control districts by using data and statistics on population level regarding sociocultural factors, population composition, birth statistics, immigrant proportion, and work participation. Randomization of districts or respondents was impossible, as NF was already implemented in the CHS in several districts. Hence, this limited the number of city districts available for inclusion, and the number of variables we were able to match for had to be adjusted for accordingly. The residential district determined the respondents’ group allocation. First-time mothers and their families in the control districts received service as usual, and the intervention districts received NF in addition to service as usual.Midwives or clinic secretaries at the CHS clinics in the five city districts recruited pregnant women attending pregnancy check-ups by screening them according to eligibility criteria and inviting them to participate. Inclusion criteria were pregnant women expecting their first child and living in one of the five city districts. The exclusion criteria were multiparous women. Women with specific conditions or diseases were not actively excluded, and no exclusion criteria were applied later based on birth outcomes. The recruiters at the CHS clinics were instructed to provide the pregnant women with initial information on the study, including a short information letter available in ten languages (Norwegian, English, Arabic, Lithuanian, Pashto, Polish, Somali, Tamil, Turkish, and Urdu). Contact information for these pregnant women was provided by the CHS clinics to researchers in the NF research project who contacted the pregnant women for inclusion in the study. The current study only includes pregnant women/first-time mothers. However, in the NF research project the women’s partners were recruited to the study by the researchers when contacting the pregnant women interested in participating.The recruitment was conducted from October 2018 to December 2019. Of the 427 pregnant women invited to participate, we included 228 pregnant women, divided by 124 pregnant women in the intervention districts and 86 pregnant women in the control districts. Due to General Data Protection Regulation laws, we were not allowed to collect any information on non-respondents.Power calculation for the NF research project were estimated based on the outcome measure of Edinburgh Postnatal Depression Scale [