Control Group Design in a Complex Intervention Study: Challenges, Dilemmas and Possible Solutions

Abstract

Background The use of a control group is one of the most critical components of an RCT. The control conditions may change over time and include assessment interviews and standard stroke treatment. Therefore, the control group should be monitored and described in as much detail as the intervention group. It is important to find ways to reduce the risk of study-induced influence on the members of the control group. The aim of this study was to explore the possible influence of the assessment interviews on the adjustment of the members of a control group in an RCT exploring psychosocial well-being following stroke. Methods Fifteen participants in the control group of the RCT, six women and nine men, aged 29-88 years, were interviewed in narrative semi-structured interviews. Ricoeur’s interpretation theory guided the analysis. Results The perceived influence of the assessment interviews on the control group varied considerably. Two different themes with subthemes were identified, describing the influence of the assessment interviews in the control group. Theme one described how participants emphasized the perceived influence of the assessment interviews that served as a safety net, enhanced their awareness and understanding, facilitated their adjustment after stroke, encouraged them to seek support, and allowed them to vent their disappointment of having been allocated to the control group. Theme two described participants’ experiences of handling their adjustment process on their own without describing any influence of the assessment interviews on their condition. These participants highlighted mild strokes, spontaneous recovery, setting own goals, support from family and friends and supporting research. Conclusions In view of the design challenges in RCTs, it seems important to explore in depth how to design assessment interviews with control group members without introducing risk of bias, and to uphold rigor and stringency in the trials.

“There is always a waitlist”: The experiences of perinatal women randomized to a waitlist condition in a trial evaluating a novel online self-directed intervention for perinatal anxiety

“…While participants in the present study initially expressed overall negative feelings and disappointment about being waitlisted, there were some participants who felt that knowing help would be coming made the six-week wait time more manageable. These results are in keeping with findings from previous non-perinatal mental health and surgical waitlist studies (8)(9)(10). Participants in the present study identified coping strategies that they found helpful during the waitlist period, many of which have been reported across the waitlist literature, in particular, peer support, self-help materials, and other professional supports (7,10).…”

“…In keeping with previous research that sought to explore the waitlist experiences of patient populations awaiting medical procedures or mental health services (e.g., surgery, mental health support) (1,(4)(5)(6)(7)(8)(9)(10)48), a qualitative design was used to describe the waitlist experiences of expectant and new mothers experiencing anxiety during the perinatal period. To understand the nuance and complexities of participants' experiences, we followed Braun and Clarke's (49,50) reflexive thematic analysis approach along with Tracy's (51) criteria for qualitative rigor.…”

“…Within the context of the COVID-19 pandemic, there have been global reports of delayed procedures and elongated waittimes for medical treatments across populations (3). Although some information is known about the effects of waitlists for patients awaiting certain healthcare services (1,(4)(5)(6), there is a lack of empirical knowledge regarding the waitlist experience from the perspective of patients awaiting mental health services (7)(8)(9)(10). Even less is known about what the waitlist experience is like for populations particularly at risk for the development or worsening of mental health problems, including pregnant and postpartum individuals (11)(12)(13)(14)(15)(16)(17)(18)(19).…”

“…Previous studies have additionally found that individuals benefit more from medical or mental health treatments if they are received in a timely manner (5,7,10). Previous qualitative studies indicated that many individuals feel disappointment about being waitlisted for medical procedures and mental health services (8)(9)(10), while others reported feelings of abandonment and decreased self-esteem in response to being waitlisted (9). However, qualitative studies have also found that participants may express gratitude for being placed on a waitlist, particularly if they feel anxious or require time to prepare themselves for an upcoming treatment or procedure (7,10).…”