Cited by 715Statistical Methods in Clinical TrialsAdvanced Causal Inference TechniquesMeta-analysis and systematic reviews

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Intention-to-Treat Analysis: Implications for Quantitative and Qualitative Research

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NEWELL, DAVID J·1992·International Journal of Epidemiology

DOI 10.1093/ije/21.5.837

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Abstract

Newell D J (Department of Medical Statistics, University of Newcastle upon Tyne, UK). Intention-to-treat analysis: implications for quantitative and qualitative research. International Journal of Epidemiology 1992, 21: 837–841 Intention-to-treat analysis is an important aspect of randomized controlled trials of health care interventions. The concept is now widely accepted in theory, but not always implemented in practice. Failure to analyse by intention-to-treat can give misleading and indeed life-threatening interpretations. In some studies, a case is put for estimating the effect that would have been observed if all patients had received the allocated treatment. Situations where this is valid are rare, but an example is given of such an exceptional study. The relevance of the intention-to-treat concept is not always taken into account in qualitative research. Interviews with new mothers who delivered their babies at home in a hypothetical controlled trial of home versus hospital confinement would provide fascinating accounts of the pleasures of successful delivery at home. But by definition the interviews would exclude the hazard and drama of necessary transfers to hospital due to complications in late pregnancy and early labour. The intention-to-treat approach would avoid this bias.

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Schwartz D, Flamant R, LeUouch i. Clinical Trials. London: Academic Press, 1980.

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Cheng, Y., Chen, Y., Lin, Y., Lu, J., Wu, S., Zhou, R., & Cheng, N. (2013) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd010583 · Cited by 7
Methods of preventing bacterial sepsis and wound complications for liver transplantation
Gurusamy, K. S., Kumar, Y., & Davidson, B. R. (2007) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd006660 · Cited by 7
Methods of cystic duct occlusion during laparoscopic cholecystectomy
Gurusamy, K. S., Bong, J. J., Fusai, G., & Davidson, B. R. (2007) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd006807 · Cited by 7
Continuous versus interrupted skin sutures for non-obstetric surgery
Gurusamy, K. S., & Davidson, B. R. (2013) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd010365 · Cited by 7
Prophylactic gastrojejunostomy for unresectable periampullary carcinoma
Gurusamy, K. S., Kumar, S., V, & Davidson, B. R. (2010) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd008533.pub2 · Cited by 7
Fibrin sealants for the prevention of postoperative pancreatic fistula following pancreatic surgery
Cheng, Y., Xiong, X., Peng, S., Wu, H. M., & Cheng, N. (2012) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd009621 · Cited by 7
Trial analysis by treatment allocated or by treatment received? Origins of ‘the intention-to-treat principle’ to reduce allocation bias: Part 1
Chalmers, I., Matthews, R., Glasziou, P., Boutron, I., & Armitage, P. (2023) · Journal of the Royal Society of Medicine · doi:10.1177/01410768231203922 · Cited by 7
Homecare interventions as a Service model for Obstructive sleep Apnea: Delivering personalised phone call using patient profiling and adherence predictions
Joymangul, J. S., Sekhari, A., Grasset, O., & Moalla, N. (2022) · International Journal of Medical Informatics · doi:10.1016/j.ijmedinf.2022.104935 · Cited by 6
Increased transparency was required when reporting imputation of primary outcome data in clinical trials
Kearney, A., Rosala‐Hallas, A., Rainford, N., Blazeby, J. M., Clarke, M. J., Lane, J. A., & Gamble, C. L. (2022) · Journal of Clinical Epidemiology · doi:10.1016/j.jclinepi.2022.02.008 · Cited by 6
New in Town—An internet-based self-efficacy intervention for internal migrants: A randomized controlled trial
Maj, A., Matynia, M., Michalak, N., Bis, A., & Andersson, G. (2024) · PLoS ONE · doi:10.1371/journal.pone.0299638 · Cited by 6
“According to the intention-to-treat concept “all patients randomly allocated to one of the treatments in a trial should be analysed together as representing that treatment, whether or not they completed, or indeed received that treatment” (p. 837) [56].”
Background
Hyperthermic intraoperative peritoneal chemotherapy and cytoreductive surgery for people with peritoneal metastases: a systematic review and cost-effectiveness analysis
Gurusamy, K. S., Leung, J., Vale, C. L., Roberts, D. A., Linden, A. H., Tan, X. W., Taribagil, P., Patel, S., Pizzo, E., Davidson, B. R., et al. (2024) · Health Technology Assessment · doi:10.3310/kwdg6338 · Cited by 6
Etidronate for the primary and secondary prevention of osteoporotic fractures in postmenopausal women
Wells, G. A., Hsieh, S., Peterson, J., Zheng, C., Kelly, S., Shea, B., & Tugwell, P. (2024) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd003376.pub4 · Cited by 6
The efficacy of a combined cognitive-behavioural and interpersonal therapy approach to the treatment of fibromyalgia syndrome : a randomized controlled trial
Langford, M. M. (2008) · Cited by 6
Early versus Delayed Oral Feeding in Patients following Total Laryngectomy
Hay, A., Pitkin, L., & Gurusamy, K. S. (2014) · Advances in Otolaryngology · doi:10.1155/2014/420239 · Cited by 6
“An intention-to-treat (ITT) analysis was performed for all outcome calculations [24].”
Method
Psychological interventions for persisting postconcussion symptoms following traumatic brain injury
Moore, P., Mawdsley, L., Jackson, C. F., & Atherton, M. J. (2017) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd012755 · Cited by 6
The Legacy for Children™ Randomized Control Trial: Effects on Cognition Through Third Grade for Young Children Experiencing Poverty
Perou, R., Robinson, L. R., Danielson, M. L., Claussen, A. H., Visser, S. N., Scott, K. G., Beckwith, L., Katz, L. F., & Smith, D. C. (2019) · Journal of Developmental & Behavioral Pediatrics · doi:10.1097/dbp.0000000000000656 · Cited by 7
Medicina basada en la evidencia. Generalidades de aplicación a la medicina nuclear. Parte I
Ruiz, S. Á., Hernández, J. C., Zárate, E. R. O. D., Colmenares, J. I. A., & Armentia, P. A. (2001) · Revista Española de Medicina Nuclear · doi:10.1016/s0212-6982(01)71966-0 · Cited by 6
Planning controlled clinical trials
Denis, L., Norlén, B. J., Holmberg, L., Begg, C. B., Damber, J. E., & Wilt, T. J. (1997) · Urology · doi:10.1016/s0090-4295(97)00161-1 · Cited by 6
Analysis and presentation
Friberg, S. G., Taube, A., Sylvester, R. J., & Oesterling, J. E. (1997) · Urology · doi:10.1016/s0090-4295(99)80324-0 · Cited by 6
Ventilator-associated pneumonia, liver disease and oral chlorhexidine
Oshodi, T. O., & Bench, S. D. (2013) · British Journal of Nursing · doi:10.12968/bjon.2013.22.13.751 · Cited by 6
The Role of Choice Architecture in Promoting Saving at Tax Time: Evidence from a Large–Scale Field Experiment
Grinstein‐Weiss, M., Cryder, C. E., Despard, M., Perantie, D. C., Oliphant, J. E., & Ariely, D. (2017) · Behavioral Science & Policy · doi:10.1177/237946151700300203 · Cited by 6
Strategies for tuberculosis control from experiences in Manila : the role of public-private collaboration and of intermittent therapy
Auer, C. (2003) · edoc (University of Basel) · doi:10.5451/unibas-002923352 · Cited by 6
“Treatment outcome was analysed using the intention-to-treat approach (Newell, 1992).”
T-tube drain in laparoscopic common bile duct stone exploration
Gurusamy, K. S., & Yu, Z. (2006) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd005641 · Cited by 6
Prophylactic gastrojejunostomy for unresectable periampullary carcinoma
Gurusamy, K. S., Kumar, S., V, & Davidson, B. R. (2010) · Cochrane Database of Systematic Reviews · doi:10.1002/14651858.cd008533 · Cited by 6
Abdominal lift for laparoscopic cholecystectomy
Gurusamy, K. S., Samraj, K., & Davidson, B. R. (2007) · doi:10.1002/14651858.cd006574 · Cited by 6

Authors: NEWELL, D. J.
Affiliations: Newcastle University (GB)
Corresponding author: NEWELL, DAVID J
ORCID: NEWELL, DAVID J
Venue: International Journal of Epidemiology
Publisher: Oxford University Press (OUP)
Published: 1992
Volume: 21
Issue: 5
Pages: 837-841
ISSN: 0300-5771 (ISSN-L)
1464-3685
DOI: 10.1093/ije/21.5.837
OpenAlex: W2106051200
Cited by: 715
References: 6
Citations by year: 2026: 4 · 2025: 15 · 2024: 24 · 2023: 22 · 2022: 21 · 2021: 16 · 2020: 16 · 2019: 16 · 2018: 25 · 2017: 36 · 2016: 31 · 2015: 35 · 2014: 51 · 2013: 62 · 2012: 34
FWCI: 5.99
Type: journal article
Language: en
Open access: bronze
doi.org
Locations: International Journal of Epidemiology (publishedVersion)
PubMed (publishedVersion)
Topics: Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
Keywords: intention-to-treat analysis, randomized controlled trials, health interventions, qualitative research, home birth, hospital confinement, allocation bias, treatment effect estimation
MeSH terms: Data Interpretation, Statistical, Evaluation Studies as Topic, Humans, Patient Compliance, Random Allocation, Research Design, Therapeutics, Cohort Studies, Randomized Controlled Trials as Topic

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Intention-to-Treat Analysis: Implications for Quantitative and Qualitative Research

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