Visits and measurements – an overview

As the present study involved many days with measurements, it was decided to conduct the study as a field study with all data collected during home visits. This was deemed the best way to maintain a sufficient number of participants in the study, since going out for frequent appointments at the hospital could be considered a barrier for participation. Appointments for the visits were made during the recruitment phone call, when the mother had decided she wanted to participate and it had been established that she and the infant fulfilled all inclusion criteria. Figure 2.1 presents a timeline for each mother-infant pair in the study.

Infant age (weeks)

≥15-16 20 ≤ 25-26 52

Figure 2.1 Timeline of participation for each mother-infant pair.

Frequency of visits

All home visits (around 370 home visits in total) were conducted by one researcher, the author. There were three visits during each of the 1st and 2nd time-points performed over a period of 8 days for the DLW method (section 2.3). In addition, a mid-way visit and a follow-up visit only included anthropometry and questionnaires.

Given that the First-Feed study was an observational study, there was no guarantee that the mothers managed exclusive breast-feeding to 6 months. Thus the timing of the 2nd time-point had to be designed as reasonably flexible, and the mother was advised to call the researcher if, at any point between the visits, she felt she was struggling with the breast-feeding. If that happened, she would be given the choice of either moving the 2nd time-point forward to be performed earlier while she was still exclusively breast-feeding, or she could introduce complementary foods and would be asked to keep a weighed record of any intake of any complementary foods during the measurement at the 2nd time- point at 25-26 weeks.

Procedures of visits

Figure 2.2 presents an overview of measurements and visits. Each participant had a copy of this flow-chart in her folder to use as a checklist. The first visit the inclusion visit (day -1), where the practicalities of the study were explained in detail to make sure that the mother knew what to expect from participating. This involved repeating the information on visits and measurements and explaining the DLW method to give the mother an understanding of the necessity for careful adherence to the procedures she would be asked to perform. After addressing any queries, written informed consent was obtained (Appendix A.3). Subsequently, measurements of maternal and infant anthropometry were performed and a pre-dose urine sample was taken while giving instructions to the mother for her to perform the subsequent urine sampling (Appendices A.5, A.6, A.8 and A.9). Finally, the mother was given questionnaires to fill in for the next day (Appendices A.4, A.10 and A.11). At visit 2 (day 0), another pre-dose urine sample was taken, the infant was weighed and the DLW was administered (Appendix A.7). For the first 12 mothers recruited to the study, anthropometric measurements which were deemed prone to intra-observer variation were repeated (section 3.2.3).

Figure 2.2 Flow-chart of visits and measurements for the First-Feed study.

Dates Times

Visit no. 1 2 3 4 5 6 7 8

Stages Recruit 1st time-point Mid-way 2nd time-point Mail Follow-up Study day of study week -1 0 1 2 3-5 6 7 0 -1 0 1 2 3-5 6 7 0

Age of infant (weeks) Information sheet and invitation to participate Recruitment; eligibility, oral information (DS1)a Written Informed Consent Background information (DS2)a Maternal anthropometry (DS3)a

Infant anthropometry (DS4)a b b

Urine sample from nappy (DS6)a Dose to the infant (DS5)a Baby Behaviour Diary (BBD) Rothbart’s Infant Behavior Questionnaire (IBQ)c

Breast-feeding practices Questionnaire (BFQ) Complementary Feeding Questionnaire (CFQ)c

The top two rows were for stating dates and times for appointments. The “white” cells were ticked off when the measurements had been performed or questionnaires had been returned.

a_{DS and number refer to number on the Data Sheet – see Appendix A.} b

Infant weight only.

c

These questionnaires will not be further described in the present thesis as the data has not been used to answer any research aims, but they are included in Appendix A for reference.

On the third visit (day 7) infant anthropometry was measured again and infant urine samples performed by the mother on days 1, 2, 6 and 7 were collected. On some occasions, dose administration was unsuccessful, and if it was possible, another attempt was made on the day after. If the second attempt was unsuccessful as well, or if it was not possible to try the day after for practical reasons, the measurement was abandoned and the third visit was cancelled. The fourth visit was the mid-way visit at 20 weeks of age, where measurements of infant anthropometry were repeated to obtain an extra data-point of growth, and the mother was given questionnaires to fill in. Visits 5 – 7 constituted the 2nd time-point, where the procedures from visits 1 – 3 were repeated (except informed consent). Finally, a follow-up visit (visit 8) was conducted at 52 weeks of infant age. On this visit, maternal and infant anthropometry was measured and the mother was given the last set of questionnaires to fill in and send back to the researcher in a pre-stamped envelope.

In general, the sequence of measurements at the visits depended very much on the infant’s temperament and routines. For instance, if the infant was asleep, time would be spent on measuring maternal anthropometry or filling out questionnaires. If the infant was hungry at the dosing visit, an attempt was made to administer the DLW at the start of the visit, and if the infant had just had a meal, the dose administration would be postponed until the end of the visit. In this way, data collection was balanced with the infant’s needs, temperament and willingness to co-operate. Due to the extra time spent on giving information and obtaining consent, this first visit usually lasted about 1½ - 2½ hours. The subsequent visits lasted from ½ – 2 hours.