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STATISTICS
Year : 2016  |  Volume : 7  |  Issue : 3  |  Page : 144-146

Common pitfalls in statistical analysis: Intention-to-treat versus per-protocol analysis


1 Department of Anaesthesiology, Tata Memorial Centre, Parel, Mumbai, Maharashtra, India
2 Department of Surgical Oncology, Division of Thoracic Surgery, Tata Memorial Centre, Parel, Mumbai, Maharashtra, India
3 Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India

Date of Web Publication28-Jun-2016

Correspondence Address:
Priya Ranganathan
Department of Anaesthesiology, Tata Memorial Centre, Ernest Borges Road, Parel, Mumbai - 400 012, Maharashtra
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2229-3485.184823

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   Abstract 

During the conduct of clinical trials, it is not uncommon to have protocol violations or inability to assess outcomes. This article in our series on common pitfalls in statistical analysis explains the complexities of analyzing results from such trials and highlights the importance of "intention-to-treat" analysis.

Keywords: Bias, biostatistics, intention-to-treat analysis


How to cite this article:
Ranganathan P, Pramesh C S, Aggarwal R. Common pitfalls in statistical analysis: Intention-to-treat versus per-protocol analysis. Perspect Clin Res 2016;7:144-6

How to cite this URL:
Ranganathan P, Pramesh C S, Aggarwal R. Common pitfalls in statistical analysis: Intention-to-treat versus per-protocol analysis. Perspect Clin Res [serial online] 2016 [cited 2022 May 23];7:144-6. Available from: https://www.picronline.org/text.asp?2016/7/3/144/184823


   Introduction Top


In interventional studies, a subset of participants often do not conform to the protocol. These "protocol violations" can be of various types: One or more participants for some reason do not receive the respective interventions to which they were randomized, inadvertently receive an intervention meant for the other trial arm, receive a prohibited concomitant intervention, or are not available for assessment of the planned outcome either because of loss to follow-up or for another reason. [1] During the analysis of the trial results, the researcher is tempted to exclude such "nonconforming" participants. The motivation is not one of deceit, but of integrity, ensuring that comparisons are made between those participants in each trial arm who strictly adhered to the planned treatment so that the true efficacy of one intervention over the other can be assessed.

However, despite the above apparent attractiveness of this approach, such exclusion poses multiple problems. [1] These include:

  1. It violates the principle of randomization. In a 2-arm study, randomization ensures comparability of the two groups, i.e., balanced for known and unknown confounders or prognostic factors, only as they were originally randomized. When some participants in either or both the groups are excluded, the remaining participants in the two groups can no longer be considered as balanced. The problem becomes larger as the number of exclusions increases
  2. At times, the noncompliance is related to a particular intervention or to disease severity. For instance, the inability to complete the scheduled treatment or appearance of unacceptable side effects may be more frequent in patients with severe disease. In addition, these may occur more often in the active treatment arm than in the placebo arm. Hence, exclusion of the participants who do not complete the treatment or follow-up as planned would lead to differential exclusion of patients with severe disease in the treated group, with the residual group unlikely to resemble the original group obtained at randomization. This may make the treatment look better than it actually is
  3. Exclusion of participants in one or both groups, particularly if their number is large, may lead to a significant reduction in sample size and hence in study power
  4. Exclusions can introduce a bias. Often the decision to exclude a particular participant is controlled, at least to some extent, by the investigator, who may be tempted to exclude patients who are not doing well in a particular arm
  5. The purpose of a trial is to assess the proportion of persons in a group who may be expected to benefit from a particular treatment. Those who do not complete treatment can of course not be expected to benefit from it. The proportion of responders among those who complete treatment thus provides an exaggerated estimate of treatment effect - this does not accurately reflect the beneficial effect that may be expected in clinical practice among those who are prescribed this particular treatment.
To obviate (or minimize) these problems, it is recommended that "intention-to-treat (ITT) analysis" be used. The principle of ITT analysis is that all participants should be analyzed in the group to which they had been randomized, i.e. as if they had received the intervention which they were supposed to receive, irrespective of the treatment actually received. Fisher defines ITT as analysis which "Includes all randomized patients in the groups to which they were randomly assigned, regardless of their adherence with the entry criteria, regardless of the treatment they actually received, and regardless of subsequent withdrawal from treatment or deviation from the protocol." [2]

The use of ITT analysis ensures maintenance of comparability between groups as obtained through randomization, maintains sample size, and eliminates bias. In addition, results obtained in such analysis more closely represent clinical practice, dealing with "effectiveness" of the intervention rather than "efficacy." In view of these advantages, ITT is today considered as a defacto standard for analysis of clinical trials, though a minority school of thought believes that this approach is too conservative. [1]

In contrast, per-protocol (PP) analysis refers to inclusion in the analysis of only those patients who strictly adhered to the protocol. The PP analysis provides an estimate of the true efficacy of an intervention, i.e., among those who completed the treatment as planned. However, as discussed above, its results do not represent the real life situation and it is likely to show an exaggerated treatment effect.

The CONSORT guidelines for reporting of "parallel group randomized controlled trials" recommend that both ITT and PP analyses should be reported for all planned outcomes to allow readers to interpret the effect of an intervention. [3]

Of course, there are some special situations. For instance, in noninferiority trials, the use of PP analysis is considered particularly important. [4] A detailed discussion of this is beyond the purview of this piece, but will be done in a subsequent article in this series.

A randomized trial published recently in the New England Journal of Medicine compared early (intervention arm) versus delayed (standard arm) introduction of allergenic foods into the diet of breast-fed children. [5] The primary outcome was the development of allergy to any food between 1 and 3 years of age. Results from the ITT analysis (1162 participants) showed no difference between groups for the primary outcome (intervention arm: 32/567 [5.6%] versus standard arm: 42/595 [7.1%]; P = ns). However, a PP analysis (732 participants) showed a significantly lower frequency of food allergy in the intervention arm versus the standard arm (5/208 [2.4%] vs. 38/524 [7.3%]; P = 0.01). It is interesting to note that only 32% (208/652) of the participants in the intervention arm adhered to the protocol as compared to 88% (524/595) of the participants in the standard arm. The authors have offered several explanations for this lack of compliance. Importantly, and in our opinion rightly, they gave precedence to the results of the ITT analysis over those of the PP analysis, and concluded that "the trial did not show the efficacy of early introduction of allergenic foods."

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
   References Top

1.
Gupta SK. Intention-to-treat concept: A review. Perspect Clin Res 2011;2:109-12.  Back to cited text no. 1
[PUBMED]  Medknow Journal  
2.
Fisher LD, Dixon DO, Herson J, Frankowski RK, Hearron MS, Peace KE. Intention to treat in clinical trials. In: Peace KE, editor. Statistical Issues in Drug Research and Development. New York: Marcel Dekker; 1990. p. 331-50.  Back to cited text no. 2
    
3.
Schulz KF, Altman DG, Moher D; CONSORT Group. CONSORT 2010 statement: Updated guidelines for reporting parallel group randomised trials. PLoS Med 2010;7:e1000251.  Back to cited text no. 3
[PUBMED]    
4.
Schumi J, Wittes JT. Through the looking glass: Understanding non-inferiority. Trials 2011;12:106.  Back to cited text no. 4
    
5.
Perkin MR, Logan K, Tseng A, Raji B, Ayis S, Peacock J, et al. Randomized trial of introduction of allergenic foods in breast-fed infants. N Engl J Med 2016;374:1733-43.  Back to cited text no. 5
    



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[Pubmed] | [DOI]
58 Improving Access to Psychological Therapies (IAPT) in the United Kingdom: A systematic review and meta-analysis of 10-years of practice-based evidence
Sarah Wakefield,Stephen Kellett,Melanie Simmonds-Buckley,Daniel Stockton,Abigail Bradbury,Jaime Delgadillo
British Journal of Clinical Psychology. 2020;
[Pubmed] | [DOI]
59 Effectiveness of LiuZiJue Qigong versus traditional core stability training for poststroke patients complicated with abnormal trunk postural control: study protocol for a single-center randomized controlled trial
Chen Wang,Long Yu,Jian Yang,Ren Wei Wang,Ya Nan Zheng,Ying Zhang
Trials. 2020; 21(1)
[Pubmed] | [DOI]
60 A study protocol for a cluster randomised controlled trial on mindfulness-based stress reduction: studying effects of mindfulness-based stress reduction and an additional organisational health intervention on mental health and work-related perceptions of teachers in Dutch secondary vocational schools
Math Janssen,Yvonne Heerkens,Beatrice Van der Heijden,Hubert Korzilius,Pascale Peters,Josephine Engels
Trials. 2020; 21(1)
[Pubmed] | [DOI]
61 Evaluation of an unconditional cash transfer program targeting children’s first-1,000–days linear growth in rural Togo: A cluster-randomized controlled trial
Justine Briaux,Yves Martin-Prevel,Sophie Carles,Sonia Fortin,Yves Kameli,Laura Adubra,Andréa Renk,Yawavi Agboka,Magali Romedenne,Félicité Mukantambara,John Van Dyck,Joachim Boko,Renaud Becquet,Mathilde Savy,Lars Åke Persson
PLOS Medicine. 2020; 17(11): e1003388
[Pubmed] | [DOI]
62 Five-Year Weight Loss Outcomes in Laparoscopic Vertical Sleeve Gastrectomy (LVSG) Versus Laparoscopic Roux-en-Y Gastric Bypass (LRYGB) Procedures: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Emma J. Osland,Rossita M. Yunus,Shahjahan Khan,Muhammed A. Memon
Surgical Laparoscopy, Endoscopy & Percutaneous Techniques. 2020; 30(6): 542
[Pubmed] | [DOI]
63 Farmacoterapia aplicada à COVID-19
Emanuella Dutra Gonçalves,Ana Luisa Marossi Justiniano,Camila de Carvalho e Freitas,Éttore Eduardo Simensato Abrame,João Remesso Ferreira Reinaldi,Laura Ribeiro de Matos
Revista Científica Multidisciplinar Núcleo do Conhecimento. 2020; : 58
[Pubmed] | [DOI]
64 A Randomized Trial of Static and Articulating Spacers for the Treatment of Infection Following Total Knee Arthroplasty
Cindy R. Nahhas,Peter N. Chalmers,Javad Parvizi,Scott M. Sporer,Keith R. Berend,Mario Moric,Antonia F. Chen,Matthew S. Austin,Gregory K. Deirmengian,Michael J. Morris,Craig J. Della Valle
The Journal of Bone and Joint Surgery. 2020; 102(9): 778
[Pubmed] | [DOI]
65 ACT Out! Social Issue Theater: A Cluster Randomized Trial with Short-term Outcomes (Preprint)
Jon Agley,Mikyoung Jun,Lori Eldridge,Daniel L Agley,Yunyu Xiao,Steve Sussman,Lilian Golzarri-Arroyo,Stephanie L Dickinson,Wasantha Jayawardene,Ruth Gassman
JMIR Mental Health. 2020;
[Pubmed] | [DOI]
66 Should chloroquine and hydroxychloroquine be used to treat COVID-19? A rapid review
Kome Gbinigie, Kerstin Frie
BJGP Open. 2020; 4(2): bjgpopen20
[Pubmed] | [DOI]
67 Study designs: Part 5 – Interventional studies (III)
Priya Ranganathan,Rakesh Aggarwal
Perspectives in Clinical Research. 2020; 11(1): 47
[Pubmed] | [DOI]
68 Effects of Dietary or Supplementary Micronutrients on Sex Hormones and IGF-1 in Middle and Older Age: A Systematic Review and Meta-Analysis
Ryan Janjuha,Diane Bunn,Richard Hayhoe,Lee Hooper,Asmaa Abdelhamid,Shaan Mahmood,Joseph Hayden-Case,Will Appleyard,Sophie Morris,Ailsa Welch
Nutrients. 2020; 12(5): 1457
[Pubmed] | [DOI]
69 Walking Green: Developing an Evidence Base for Nature Prescriptions
Elizabeth P.D. Koselka,Lucy C. Weidner,Arseniy Minasov,Marc G. Berman,William R. Leonard,Marianne V. Santoso,Junia N. de Brito,Zachary C. Pope,Mark A. Pereira,Teresa H. Horton
International Journal of Environmental Research and Public Health. 2019; 16(22): 4338
[Pubmed] | [DOI]
70 Results of a multicentre double-blind placebo-controlled randomized trial of the liquid form of Anaferon for children in the treatment of acute upper respiratory tract infections
B. M. Blokhin,O. V. Shamsheva,N. L. Chernaya,I. G. Sitnikov,S. G. Lazareva,N. B. Balzerovich,O. A. Perminova,O. V. Zhiglinskaya,M. Yu. Koshavtseva
Rossiyskiy Vestnik Perinatologii i Pediatrii (Russian Bulletin of Perinatology and Pediatrics). 2019; 64(4): 105
[Pubmed] | [DOI]
71 Women in LOVe: Lacto-Ovo-Vegetarian Diet Rich in Omega-3 Improves Vasomotor Symptoms in Postmenopausal Women. An Exploratory Randomized Controlled Trial
Ornella Rotolo,Iris Zinzi,Nicola Veronese,Anna M. Cisternino,Rosa Reddavide,Rosa Inguaggiato,Gioacchino Leandro,Maria Notarnicola,Valeria Tutino,Valentina De Nunzio,Giampiero De Leonardis,Vito Guerra,Rossella Donghia,Fabio Fucilli,Raffaella Licinio,Anna Mastrosimini,Caterina C.M. Rinaldi,Tiziana Daddabbo,Nicola Giampaolo,Palma A. Iacovazzi,Sara Giannico,Maria G. Caruso
Endocrine, Metabolic & Immune Disorders - Drug Targets. 2019; 19(8): 1232
[Pubmed] | [DOI]
72 One Drop with an Activity Tracker for Adults with Type 1 Diabetes: Randomized Control Trial (Preprint)
Chandra Y. Osborn,Ashley Hirsch,Lindsay Sears,Mark Heyman,Jennifer Raymond,Brian Huddleston,Jeff Dachis
JMIR mHealth and uHealth. 2019;
[Pubmed] | [DOI]
73 Methods for the Watch the Spot Trial. A Pragmatic Trial of More- versus Less-Intensive Strategies for Active Surveillance of Small Pulmonary Nodules
Michael K. Gould,Rebecca Smith-Bindman,Karen Kelly,Danielle E. Altman,Igor Barjaktarevic,Beth Creekmur,Evan de Bie,Debra S. Dyer,Eduardo J. Mortani Barbosa,Richard A. Mularski,Lihong Qi,Laszlo T. Vaszar,Sophronia Yu,Diana L. Miglioretti
Annals of the American Thoracic Society. 2019; 16(12): 1567
[Pubmed] | [DOI]
74 A randomized, open-label clinical trial comparing the long-term effects of miltefosine and meglumine antimoniate for mucosal leishmaniasis
Raimunda Nonata Ribeiro Sampaio,Juliana Saboia Fontenele e Silva,Carmen Dea Ribeiro de Paula,Cláudia Porto,Jorgeth de Oliveira Carneiro da Motta,Ledice Inacia de Araujo Pereira,Sofia Sales Martins,Daniel Holanda Barroso,Gustavo Subtil Magalhães Freire,Ciro Martins Gomes
Revista da Sociedade Brasileira de Medicina Tropical. 2019; 52(0)
[Pubmed] | [DOI]
75 The CABANA Debate – Once a Treatment Becomes Popular, it is Hard to Interpret the Results in Medicine
Ozcan Ozeke,Serkan Cay,Firat Ozcan,Serkan Topaloglu,Dursun Aras
European Journal of Arrhythmia & Electrophysiology. 2019; 5(1): 17
[Pubmed] | [DOI]
76 Iron-containing cookware for the reduction of iron deficiency anemia among children and females of reproductive age in low- and middle-income countries: A systematic review
Clark Alves,Ahlam Saleh,Halimatou Alaofè,Joann M. McDermid
PLOS ONE. 2019; 14(9): e0221094
[Pubmed] | [DOI]
77 Variations in study outcomes relative to intention-to-treat and per-protocol data analysis techniques in the evaluation of efficacy for treatment of venous leg ulcers with dehydrated human amnion/chorion membrane allograft
Christian Bianchi,William Tettelbach,Niki Istwan,Brandon Hubbs,Kimberly Kot,Stan Harris,Donald Fetterolf
International Wound Journal. 2019;
[Pubmed] | [DOI]
78 Randomized Controlled Trials and Quasi-Experimental Studies Published in Nursing Journals: Findings From a Scoping Review With Implications for Further Research
Silvia Gonella,Paola Di Giulio,Alvisa Palese,Valerio Dimonte,Sara Campagna
Worldviews on Evidence-Based Nursing. 2019;
[Pubmed] | [DOI]
79 Use of a Bidirectional Text Messaging System for Emergency Department Follow-Up Versus Usual Follow-Up
Brooks J. Obr,Tracy Young,Karisa K. Harland,Andrew Nugent
Telemedicine and e-Health. 2019;
[Pubmed] | [DOI]
80 Findings From a Real-World Translation Study of the Evidence-Based “Partners in Dementia Care”
David M Bass,Thomas Hornick,Mark Kunik,Katherine S Judge,Branka Primetica,Keith Kearney,Julie Rentsch,Catherine Mccarthy,Jennifer Grim,J Jill Suitor
Innovation in Aging. 2019; 3(3)
[Pubmed] | [DOI]
81 Effectiveness of Interventions for Preventing People With Dementia Exiting or Getting Lost
Luke Emrich-Mills,Vaisakh Puthusseryppady,Michael Hornberger,Patricia C. Heyn
The Gerontologist. 2019;
[Pubmed] | [DOI]
82 Response to Comment on “Letter to the Editor”
Hendrike E. Bolkenstein,Esther C. J. Consten,Ivo A. M. J. Broeders,Werner A. Draaisma
Annals of Surgery. 2019; 270(6): e102
[Pubmed] | [DOI]
83 Open reduction and plate fixation compared with non-surgical treatment for displaced midshaft clavicle fracture
Miao Qin,Shishun Zhao,Wenlai Guo,Li Tang,Hangyu Li,Xuejie Wang,Zhe Zhu,Tianwen Sun
Medicine. 2019; 98(20): e15638
[Pubmed] | [DOI]
84 Effectiveness of prophylactic sacral protective dressings to prevent pressure injury: a systematic review and meta-analysis
Paul Fulbrook,Vainess Mbuzi,Sandra Miles
International Journal of Nursing Studies. 2019; : 103400
[Pubmed] | [DOI]
85 Does Lifestyle Intervention After Gastric Bypass Surgery Prevent Weight Regain? A Randomized Clinical Trial
Susanna E. Hanvold,Kathrine J. Vinknes,Elin B. Løken,Anette Hjartåker,Ole Klungsøyr,Eline Birkeland,Hilde Risstad,Hanne L. Gulseth,Helga Refsum,Anne-Marie Aas
Obesity Surgery. 2019;
[Pubmed] | [DOI]
86 GRADE-ing the Benefit/Risk Equation in Food Immunotherapy
Bettina Duca,Nandinee Patel,Paul J. Turner
Current Allergy and Asthma Reports. 2019; 19(6)
[Pubmed] | [DOI]
87 Practical and Conceptual Considerations for the Primary Prevention of Asthma
Steven M. Brunwasser,Tina V. Hartert
Clinics in Chest Medicine. 2019; 40(1): 1
[Pubmed] | [DOI]
88 The Effect of HIV Self-Testing Delivery Models on Female Sex Workers’ Sexual Behaviors: A Randomized Controlled Trial in Urban Uganda
Katrina F. Ortblad,Daniel Kibuuka Musoke,Thomson Ngabirano,Aidah Nakitende,Guy Harling,Jessica E. Haberer,Margaret McConnell,Joshua A. Salomon,Catherine E. Oldenburg,Till Bärnighausen
AIDS and Behavior. 2019;
[Pubmed] | [DOI]
89 The effect of ‘Zesy002’ kiwifruit (Actinidia chinensis var. chinensis) on gut health function: a randomised cross-over clinical trial
Sarah L. Eady,Alison J. Wallace,Christine A. Butts,Duncan Hedderley,Lynley Drummond,Juliet Ansell,Richard B. Gearry
Journal of Nutritional Science. 2019; 8
[Pubmed] | [DOI]
90 Modeling HPV vaccination scale-up among urban young men who have sex with men in the context of HIV
Neal D. Goldstein,Michael T. LeVasseur,Nguyen K. Tran,Jonathan Purtle,Seth L. Welles,Stephen C. Eppes
Vaccine. 2019;
[Pubmed] | [DOI]
91 The effects of medication adherence on study outcomes in randomized clinical trials: a role for cognitive dysfunction?
V. Sanborn,M. A. Azcarate-Peril,J. Gunstad
Applied Neuropsychology: Adult. 2019; : 1
[Pubmed] | [DOI]
92 *The efficacy of the attachment-based SAFE® prevention program: a randomized control trial including mothers and fathers
I. Walter,S. Landers,J. Quehenberger,E. Carlson,K. H. Brisch
Attachment & Human Development. 2019; : 1
[Pubmed] | [DOI]
93 Prevention Science and Child/Youth Development: Randomized Explanatory Trials for Integrating Theory, Method, and Analysis in Program Evaluation
James Jaccard,Ai Bo
Journal of the Society for Social Work and Research. 2018; : 000
[Pubmed] | [DOI]
94 Anti-androgen monotherapy versus gonadotropin-releasing hormone agonists in men with advanced, non-metastatic prostate cancer: a register-based, observational study
Frederik Birkebæk Thomsen,Cecilia Bosco,Hans Garmo,Jan Adolfsson,Niklas Hammar,Pär Stattin,Mieke Van Hemelrijck
Acta Oncologica. 2018; : 1
[Pubmed] | [DOI]
95 Reducing Stress and Enhancing Academic Buoyancy among Adolescents Using a Brief Web-based Program Based on Acceptance and Commitment Therapy: A Randomized Controlled Trial
Anne Puolakanaho,Raimo Lappalainen,Päivi Lappalainen,Joona S. Muotka,Riikka Hirvonen,Kenneth M. Eklund,Timo P. S. Ahonen,Noona Kiuru
Journal of Youth and Adolescence. 2018;
[Pubmed] | [DOI]
96 Elective replacement of intravenous cannula in neonates—a randomised trial
Li Yen Chin,Timothy A. Walsh,Karen Van Haltren,Laura Hayden,Miranda Davies-Tuck,Atul Malhotra
European Journal of Pediatrics. 2018;
[Pubmed] | [DOI]
97 John Charnley Award
Michael J. Taunton,Robert T. Trousdale,Rafael J. Sierra,Ken Kaufman,Mark W. Pagnano
Clinical Orthopaedics and Related Research. 2018; 476(2): 216
[Pubmed] | [DOI]
98 Assessment of collagen fiber orientation dispersion in articular cartilage by small-angle X-ray scattering and diffusion tensor imaging: Preliminary results
Sirisha Tadimalla,Monique C. Tourell,Robert Knott,Konstantin I. Momot
Magnetic Resonance Imaging. 2018;
[Pubmed] | [DOI]
99 Dietary therapy and non-surgical periodontal treatment in obese patients with chronic periodontitis
Mayte Martinez-Herrera,Sandra López-Domènech,Francisco Javier Silvestre,Javier Silvestre-Rangil,Celia Bañuls,Antonio Hernández-Mijares,Milagros Rocha
Journal of Clinical Periodontology. 2018;
[Pubmed] | [DOI]
100 Effectiveness of deltamethrin-impregnated dog collars on the incidence of canine infection by Leishmania infantum: A large scale intervention study in an endemic area in Brazil
Wendel Coura-Vital,Gleisiane Gomes de Almeida Leal,Luana Araújo Marques,Aimara da Costa Pinheiro,Mariângela Carneiro,Alexandre Barbosa Reis,Knut Stieger
PLOS ONE. 2018; 13(12): e0208613
[Pubmed] | [DOI]
101 Predictors of discontinuation, efficacy, and safety of memantine treatment for Alzheimer’s disease: meta-analysis and meta-regression of 18 randomized clinical trials involving 5004 patients
Lídia Blanco-Silvente,Dolors Capellà,Josep Garre-Olmo,Joan Vilalta-Franch,Xavier Castells
BMC Geriatrics. 2018; 18(1)
[Pubmed] | [DOI]
102 Liuzijue Qigong vs traditional breathing training for patients with post-stroke dysarthria complicated with abnormal respiratory control: study protocol of a single center randomized controlled trial
Hongli Li,Gaiyan Li,Gongliang Liu,Ying Zhang
Trials. 2018; 19(1)
[Pubmed] | [DOI]
103 Direct provision versus facility collection of HIV self-tests among female sex workers in Uganda: A cluster-randomized controlled health systems trial
Katrina Ortblad,Daniel Kibuuka Musoke,Thomson Ngabirano,Aidah Nakitende,Jonathan Magoola,Prossy Kayiira,Geoffrey Taasi,Leah G. Barresi,Jessica E. Haberer,Margaret A. McConnell,Catherine E. Oldenburg,Till Bärnighausen,Elvin H. Geng
PLOS Medicine. 2017; 14(11): e1002458
[Pubmed] | [DOI]
104 Efficacy of antidepressants: bias in randomized clinical trials and related issues
Sheng-Min Wang,Changsu Han,Soo-Jung Lee,Tae-Youn Jun,Ashwin A. Patkar,Prakash S. Masand,Chi-Un Pae
Expert Review of Clinical Pharmacology. 2017; : 1
[Pubmed] | [DOI]
105 Konjenital Musku¨ler Tortikollis ve Birlikte Gelisen Deformasyonel Plagiosefalinin Ev Fizyoterapi Programina Yanitlarinin Incelenmesi
Hilal KEKLICEK,Fatma UYGUR
Türk Fizyoterapi ve Rehabilitasyon Dergisi. 2017;
[Pubmed] | [DOI]



 

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