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Gharacheh M, Khalajabadi Farahani F, Jahanfar S, Ranjbar F. Challenges in Conducting Longitudinal Interventional Research in Developing Countries: Lessons From a Nationwide Clinical Trial. IJN 2025; 38 (S1 )
URL: http://ijn.iums.ac.ir/article-1-3983-en.html
URL: http://ijn.iums.ac.ir/article-1-3983-en.html
1- Nursing and Midwifery Care Research Center, Health Management Research Institute, Iran University of Medical Sciences, Tehran, Iran.
2- Family Research Institute, Shahid Beheshti University, Tehran, Iran.
3- Department of Public Health and Community Medicine, School of Medicine, University of Tufts, Boston, USA.
4- Nursing and Midwifery Care Research Center, Health Management Research Institute, Iran University of Medical Sciences, Tehran, Iran. ,ranjbar.f@iums.ac.ir
2- Family Research Institute, Shahid Beheshti University, Tehran, Iran.
3- Department of Public Health and Community Medicine, School of Medicine, University of Tufts, Boston, USA.
4- Nursing and Midwifery Care Research Center, Health Management Research Institute, Iran University of Medical Sciences, Tehran, Iran. ,
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Dear Editor
onducting longitudinal interventional research in developing countries, including Iran, is a unique challenge that can significantly impact study outcomes. This letter shares lessons from a nationwide clinical trial with a follow-up period conducted by Gharacheh et al. in 2020, in Iran, and reports the barriers they faced. Identifying these obstacles can be beneficial for future research [1]. In this clinical trial, the study aimed to evaluate the effectiveness of a fertility education program in enhancing fertility knowledge, childbearing intentions, and the rate of planned pregnancies among couples seeking premarital counseling. The study encountered several significant challenges that adversely affected participant engagement and data collection. The COVID-19 pandemic led to the closure of premarital education classrooms, making in-person training impractical and prompting a complete redesign of the educational content using multimedia via social media platforms (e.g., WhatsApp).
Given the pandemic and the risks associated with in-person recruitment, informed consent forms and questionnaires were made available online, and the link to participate in the study was distributed via social media or text messages. Following the pandemic, social unrest, and restrictions on popular social media in Iran in 2022, significantly hindered contact with participants and eroded trust in researchers. Despite coordination efforts—including a dedicated website for downloading educational content, SMS reminders, telephone follow-ups, and web-based questionnaires—the response rate remained markedly low. The challenging social conditions within the community created an unfavorable environment for data collection; consequently, only 826 out of 2,480 participants in the initial post-intervention phase provided responses. After marriage, many participants no longer had ongoing contact with the researchers, making it difficult to encourage continued participation. Additionally, cultural sensitivities surrounding fertility and childbearing exacerbated these challenges. Changes in participants’ living conditions, such as alterations in contact information, immigration, or separation/divorce, further hindered recruitment and retention efforts. Significant staff turnover and challenges due to high annual inflation affected the program follow-up. Overall, these factors compromised the feasibility of conducting the subsequent phases of the clinical trial and indicated a need to revise the protocol for future studies. Consequently, given an approximate 33% response rate, it was decided not to analyze post-intervention data. The low level of participation raises substantial concerns about the generalizability of the findings and suggests that the perspectives and experiences of most participants were not adequately captured.
A similar randomized controlled trial conducted in Japan by Maeda et al. [2] in 2018, investigated the long-term effects of fertility education on knowledge and reproductive outcomes. This study also faced limitations, including a high attrition rate, particularly among younger participants. Their findings indicated that while one-time education can yield lasting knowledge, follow-up sessions may enhance retention and support informed reproductive decision-making, especially among younger participants. The authors proposed that future research should focus on controlled trials and innovative strategies to maintain engagement in fertility education. Therefore, conventional participant retention strategies, including pilot study, community engagement, and reminders, alone are insufficient to improve retention in contexts similar to ours in low- and middle-income countries.
For effective retention, strategies include: Using an electronic database, maintaining detailed cohort contact information, enhancing engagement through communication and feedback, implementing concise questionnaire tools, and offering appropriate incentives. Key facilitators for participant retention include financial incentives, involving key community members, offering a flexible schedule, and fostering trust and personal connections with participants. Additionally, maintaining comprehensive contact information for participants is essential. Conducting robust longitudinal studies can be costly, and funding delays may impede follow-up, particularly in regions with high populations. To facilitate follow-ups, researchers should consider implementing data identifiers while addressing concerns about protecting participants’ identities.
Lloyd-Johnsen et al. [6] emphasized the importance of aligning research initiatives with social values and priorities to ensure relevance and impact. They recommend that researchers should limit their scope to what is essential only to avoid unnecessary complications. Flexibility in research design is crucial to minimize participants’ workload. Significant barriers to the development, implementation, and publication of studies include time and funding limitations, which can hinder the overall effectiveness and applicability of research outcomes. A study conducted by Palese et al. during the COVID-19 pandemic highlighted the benefits of a multidisciplinary approach that incorporates patients’ perspectives to safeguard research consistency and quality. Common retention strategies included the use of reminders, emphasis on study benefits, and effective contact and scheduling strategies. Research teams should be well-organized and maintain continuity, adapting their strategies to the participants and using innovations as necessary.
Attention to cultural sensitivities in applying retention strategies is crucial, and further research is needed to understand how these strategies vary globally. A study suggested that strategies aimed at reducing participant burden, such as flexibility in data collection methods, may be particularly effective in maximizing cohort retention.
Ultimately, conducting large-scale longitudinal interventional studies in developing countries requires a careful approach that considers the unique challenges of these countries. The importance and benefits of participating in these studies may not be fully understood by individuals in developed countries. By considering social values, adopting flexible and culturally adaptive methods, and focusing on manageable sample sizes, researchers can enhance the reliability and impact of their work. Additionally, addressing time and budget constraints is crucial for the successful implementation and publication of research findings. Therefore, in countries with low income, such as Iran, the use of large sample sizes in longitudinal interventional studies is not recommended; instead, smaller, more manageable cohorts can yield more reliable data. Furthermore, future studies should emphasize strategies for increasing participant recruitment and retention to improve response rates and strengthen the overall validity of the findings.
References
1. Gharacheh M, Khalajabadi Farahani F, Mirghafourvand M, Janani L, Ranjbar F. A multicenter randomized controlled trial protocol to evaluate the effectiveness of an educational intervention on fertility knowledge, intention and behavior among Iranian new couples. BMC Public Health. 2020; 20(1):1917. [DOI:10.1186/s12889-020-10029-4] [PMID]
2. Maeda E, Boivin J, Toyokawa S, Murata K, Saito H. Two-year follow-up of a randomized controlled trial: knowledge and reproductive outcome after online fertility education. Hum Reprod. 2018; 33(11):2035-42. [DOI:10.1093/humrep/dey293] [PMID]
3. Rispel LC, Ditlopo P, White J, Blaauw D. Methodological considerations in establishing and maintaining longitudinal health workforce studies: Lessons learned from the WiSDOM cohort in South Africa. Glob Health Action. 2021; 14(1):1996688. [DOI:10.1080/16549716.2021.1996688] [PMID]
4. Singh P, Ens T, Hayden KA, Sinclair S, LeBlanc P, Chohan M, et al. Retention of Ethnic Participants in Longitudinal Studies. J Immigr Minor Health. 2018; 20(4):1011-24. [DOI:10.1007/s10903-017-0618-0] [PMID]
5. Banati P. Sustainable Human Development Across the Life Course: Evidence from Longitudinal Research. Bristol, UK: Bristol University Press; 2021. [DOI:10.1332/policypress/9781529204827.001.0001]
6. Lloyd-Johnsen C, D’Aprano A, Goldfeld S, Eades S. Challenges and lessons learnt implementing longitudinal studies of Aboriginal and Torres Strait Islander children and young people: A qualitative study. First Nations Health and Wellbeing - Lowitja J. 2024; 2:100029. [DOI:10.1016/j.fnhli.2024.100029]
7. Palese A, Chiappinotto S, Fonda F, Visintini E, Peghin M, Colizzi M, et al. Lessons learnt while designing and conducting a longitudinal study from the first Italian COVID-19 pandemic wave up to 3 years. Health Res Policy Sys. 2023; 21(1):111. [DOI:10.1186/s12961-023-01055-w] [PMID]
8. Abshire M, Dinglas VD, Cajita MI, Eakin MN, Needham DM, Himmelfarb CD. Participant retention practices in longitudinal clinical research studies with high retention rates. BMC Med Res Methodol. 2017; 17(1):30. [DOI:10.1186/s12874-017-0310-z] [PMID]
9. Teague S, Youssef GJ, Macdonald JA, Sciberras E, Shatte A, Fuller-Tyszkiewicz M, et al. Retention strategies in longitudinal cohort studies: a systematic review and meta-analysis. BMC Med Res Methodol. 2018; 18(1):151. [DOI:10.1186/s12874-018-0586-7] [PMID]
onducting longitudinal interventional research in developing countries, including Iran, is a unique challenge that can significantly impact study outcomes. This letter shares lessons from a nationwide clinical trial with a follow-up period conducted by Gharacheh et al. in 2020, in Iran, and reports the barriers they faced. Identifying these obstacles can be beneficial for future research [1]. In this clinical trial, the study aimed to evaluate the effectiveness of a fertility education program in enhancing fertility knowledge, childbearing intentions, and the rate of planned pregnancies among couples seeking premarital counseling. The study encountered several significant challenges that adversely affected participant engagement and data collection. The COVID-19 pandemic led to the closure of premarital education classrooms, making in-person training impractical and prompting a complete redesign of the educational content using multimedia via social media platforms (e.g., WhatsApp).
Given the pandemic and the risks associated with in-person recruitment, informed consent forms and questionnaires were made available online, and the link to participate in the study was distributed via social media or text messages. Following the pandemic, social unrest, and restrictions on popular social media in Iran in 2022, significantly hindered contact with participants and eroded trust in researchers. Despite coordination efforts—including a dedicated website for downloading educational content, SMS reminders, telephone follow-ups, and web-based questionnaires—the response rate remained markedly low. The challenging social conditions within the community created an unfavorable environment for data collection; consequently, only 826 out of 2,480 participants in the initial post-intervention phase provided responses. After marriage, many participants no longer had ongoing contact with the researchers, making it difficult to encourage continued participation. Additionally, cultural sensitivities surrounding fertility and childbearing exacerbated these challenges. Changes in participants’ living conditions, such as alterations in contact information, immigration, or separation/divorce, further hindered recruitment and retention efforts. Significant staff turnover and challenges due to high annual inflation affected the program follow-up. Overall, these factors compromised the feasibility of conducting the subsequent phases of the clinical trial and indicated a need to revise the protocol for future studies. Consequently, given an approximate 33% response rate, it was decided not to analyze post-intervention data. The low level of participation raises substantial concerns about the generalizability of the findings and suggests that the perspectives and experiences of most participants were not adequately captured.
A similar randomized controlled trial conducted in Japan by Maeda et al. [2] in 2018, investigated the long-term effects of fertility education on knowledge and reproductive outcomes. This study also faced limitations, including a high attrition rate, particularly among younger participants. Their findings indicated that while one-time education can yield lasting knowledge, follow-up sessions may enhance retention and support informed reproductive decision-making, especially among younger participants. The authors proposed that future research should focus on controlled trials and innovative strategies to maintain engagement in fertility education. Therefore, conventional participant retention strategies, including pilot study, community engagement, and reminders, alone are insufficient to improve retention in contexts similar to ours in low- and middle-income countries.
For effective retention, strategies include: Using an electronic database, maintaining detailed cohort contact information, enhancing engagement through communication and feedback, implementing concise questionnaire tools, and offering appropriate incentives. Key facilitators for participant retention include financial incentives, involving key community members, offering a flexible schedule, and fostering trust and personal connections with participants. Additionally, maintaining comprehensive contact information for participants is essential. Conducting robust longitudinal studies can be costly, and funding delays may impede follow-up, particularly in regions with high populations. To facilitate follow-ups, researchers should consider implementing data identifiers while addressing concerns about protecting participants’ identities.
Lloyd-Johnsen et al. [6] emphasized the importance of aligning research initiatives with social values and priorities to ensure relevance and impact. They recommend that researchers should limit their scope to what is essential only to avoid unnecessary complications. Flexibility in research design is crucial to minimize participants’ workload. Significant barriers to the development, implementation, and publication of studies include time and funding limitations, which can hinder the overall effectiveness and applicability of research outcomes. A study conducted by Palese et al. during the COVID-19 pandemic highlighted the benefits of a multidisciplinary approach that incorporates patients’ perspectives to safeguard research consistency and quality. Common retention strategies included the use of reminders, emphasis on study benefits, and effective contact and scheduling strategies. Research teams should be well-organized and maintain continuity, adapting their strategies to the participants and using innovations as necessary.
Attention to cultural sensitivities in applying retention strategies is crucial, and further research is needed to understand how these strategies vary globally. A study suggested that strategies aimed at reducing participant burden, such as flexibility in data collection methods, may be particularly effective in maximizing cohort retention.
Ultimately, conducting large-scale longitudinal interventional studies in developing countries requires a careful approach that considers the unique challenges of these countries. The importance and benefits of participating in these studies may not be fully understood by individuals in developed countries. By considering social values, adopting flexible and culturally adaptive methods, and focusing on manageable sample sizes, researchers can enhance the reliability and impact of their work. Additionally, addressing time and budget constraints is crucial for the successful implementation and publication of research findings. Therefore, in countries with low income, such as Iran, the use of large sample sizes in longitudinal interventional studies is not recommended; instead, smaller, more manageable cohorts can yield more reliable data. Furthermore, future studies should emphasize strategies for increasing participant recruitment and retention to improve response rates and strengthen the overall validity of the findings.
References
1. Gharacheh M, Khalajabadi Farahani F, Mirghafourvand M, Janani L, Ranjbar F. A multicenter randomized controlled trial protocol to evaluate the effectiveness of an educational intervention on fertility knowledge, intention and behavior among Iranian new couples. BMC Public Health. 2020; 20(1):1917. [DOI:10.1186/s12889-020-10029-4] [PMID]
2. Maeda E, Boivin J, Toyokawa S, Murata K, Saito H. Two-year follow-up of a randomized controlled trial: knowledge and reproductive outcome after online fertility education. Hum Reprod. 2018; 33(11):2035-42. [DOI:10.1093/humrep/dey293] [PMID]
3. Rispel LC, Ditlopo P, White J, Blaauw D. Methodological considerations in establishing and maintaining longitudinal health workforce studies: Lessons learned from the WiSDOM cohort in South Africa. Glob Health Action. 2021; 14(1):1996688. [DOI:10.1080/16549716.2021.1996688] [PMID]
4. Singh P, Ens T, Hayden KA, Sinclair S, LeBlanc P, Chohan M, et al. Retention of Ethnic Participants in Longitudinal Studies. J Immigr Minor Health. 2018; 20(4):1011-24. [DOI:10.1007/s10903-017-0618-0] [PMID]
5. Banati P. Sustainable Human Development Across the Life Course: Evidence from Longitudinal Research. Bristol, UK: Bristol University Press; 2021. [DOI:10.1332/policypress/9781529204827.001.0001]
6. Lloyd-Johnsen C, D’Aprano A, Goldfeld S, Eades S. Challenges and lessons learnt implementing longitudinal studies of Aboriginal and Torres Strait Islander children and young people: A qualitative study. First Nations Health and Wellbeing - Lowitja J. 2024; 2:100029. [DOI:10.1016/j.fnhli.2024.100029]
7. Palese A, Chiappinotto S, Fonda F, Visintini E, Peghin M, Colizzi M, et al. Lessons learnt while designing and conducting a longitudinal study from the first Italian COVID-19 pandemic wave up to 3 years. Health Res Policy Sys. 2023; 21(1):111. [DOI:10.1186/s12961-023-01055-w] [PMID]
8. Abshire M, Dinglas VD, Cajita MI, Eakin MN, Needham DM, Himmelfarb CD. Participant retention practices in longitudinal clinical research studies with high retention rates. BMC Med Res Methodol. 2017; 17(1):30. [DOI:10.1186/s12874-017-0310-z] [PMID]
9. Teague S, Youssef GJ, Macdonald JA, Sciberras E, Shatte A, Fuller-Tyszkiewicz M, et al. Retention strategies in longitudinal cohort studies: a systematic review and meta-analysis. BMC Med Res Methodol. 2018; 18(1):151. [DOI:10.1186/s12874-018-0586-7] [PMID]
Type of Study: Letter to the Editor |
Subject:
Midwifery
Received: 2025/12/28 | Accepted: 2025/12/22 | Published: 2025/03/21
Received: 2025/12/28 | Accepted: 2025/12/22 | Published: 2025/03/21
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