Table 1 Proof-of-concept study research questions, outcomes and analysis
From: Digital screening for postnatal depression: mixed methods proof-of-concept study
Concept | Research question | Outcome(s) | Analysis |
|---|---|---|---|
Feasibility | Is it feasible to use a smartphone app to screen for parental postnatal depression from late pregnancy until 6 weeks postpartum? | Measures of feasibility: • Study recruitment rate • Reasons for declining to participate • Study dropout rate • Percentage of daily app assessments completed during the app-use phase • Percentage of participants completing ≥ 33% of app assessments • Percentage of participants completing ≥ 50% of app assessments | • Descriptive statistics of all listed measures of feasibility • The a priori “accept” criterion for app engagement was ≥ 33% daily EPDS completed across the sample, with the “target” criterion being 50% of participants submitting 50% of data entries |
Patterns of app use | Which parents engage most with the app? How do users’ app use patterns change over time? | • Baseline clinical/demographic information • Percentage daily app use in the app use period • Level of app use per week of the study | • Effects of baseline variables on percentage daily app use examined using Spearman’s correlation (continuous variables), Mann–Whitney or Kruskal–Wallis tests (categorical variables) • Pattern of app completion over time examined using mixed effects models (random effect of participant; fixed effect of time; percentage app completion as the dependent variable) |
Validity | Is it valid to use a smartphone app for this purpose? | Data from first and last weeks of app-use phase: • App-generated daily EPDS (up to 7 data-points per person per week, averaged across the week for comparison with paper EPDS) • Gold-standard weekly paper EPDS | Agreement between app and paper EPDS data examined for two separate one-week periods using: • Intra-class correlation (total EPDS scores, continuous variable) • Weighted kappa (individual item scores, ordinal) |
Safety | Is it safe to use a smartphone app for this purpose? | • Number of minor and major adverse events during the study | • Descriptive statistics of the number of minor/major adverse events and whether these appear to be are related/unrelated to app use |
Usability and acceptability | Is the app easy to use? Do parents find it acceptable to use a smartphone app for this purpose? | • Abridged Mobile App Rating Scale • Qualitative interview data regarding usability and acceptability of the app | • Descriptive statistics of quantitative data from the abridged Mobile App Rating Scale • Framework analysis of qualitative data (a priori themes relating to usability/acceptability) |
User experiences (follow-up paper) | What are parents’ experiences of using an app for this purpose? What are parents’ experiences of the study procedures? | • Qualitative interview data regarding experiences of app use and study procedures | • Framework analysis of qualitative data (a posteriori themes), to be published in a follow-up paper |