Table 5 Framework for the integration of innovative qualitative methods into randomised controlled trials of complex health interventions

Background and setting

Ensure relevance of the problem to the context

Affects applicability, acceptability, sustainability and transferability of potential positive findings

N/A

External

To identify social, cultural, health, economic or political factors that might affect uptake and sustainability of positive results

Direct observation, ideally in-depth but if time or resources are limited, as part of a rapid ethnographic appraisal or Broad Brush Survey

Obtain buy-in from stakeholders

Reduces translation and sustainability of results into changes in policy and practices

N/A

External

To overcome potential barriers to implementation and promote uptake of intervention

In-depth interviews with policymakers and stakeholders | Document analysis

Intervention design and compliance

Ensure cultural acceptability and practical feasibility of the intervention

Impacts adherence and increases number of drop-outs

Adherence Withdrawal

Internal

To tailor intervention in order to increase retention and adherence

Diary methods – via Interactive voice responses or SMS

Recruitment and enrolment

Guarantee representativeness of the sample and efficient recruitment methods

Risks achieving the required sample size to detect significant effect

Selection

Internal

External

To determine the best possible recruitment method to reach target population

Community mapping | Spiral walks

Randomization and allocation

Guarantee balanced randomization

Reduces comparability between groups

Selection

Confounding

Internal

External

To identify contextual factors that can affect the effect of the intervention and reduce comparability between groups

Observation | Public randomization

Participant follow-up

Minimize the number of participants leaving the study

Enables unequal loss of participants between groups which can affect causal inference

Attrition

Confounding (if differential attrition between trial arms)

Internal

External

To prevent or understand reasons for loss to follow-up and improve retention strategies

Diary methods, mobile-based methods such as interactive voice response on SMS / WhatsApp | peer support for adherence

Improve adherence to the intervention

Modifies the magnitude/direction of effect

Adherence

Internal

To understand reasons for non-adherence to the intervention

Data collection

Enhance reliability and quality of data

Allows inconsistent or unreliable measurements which can affect the observed magnitude and direction of the effect

Instrument

Internal

To avoid or identify errors in the measurement and data collection process.

Co-designing measurement tools with participants | Qualitative tool validation

Maintain objectivity during the data collection process

Threatens the validity of the data collected and/or measured to answer the objective

Instrument

Recall

Social desirability

Internal

To assess and validate the process of data collection.

FGD with prompts such as flashcards or images

Pair interviews and role playing

Analysis and results

Identify the mechanisms underpinning the effect of the intervention

Limits an informed discussion of the results (negative or positive)

N/A

External

To triangulate the quantitative findings and identify contextual information that may have affected the results

Participatory Analysis methods