Tavistock Adult Depression Study (TADS): A randomised controlled trial of psychoanalytic psychotherapy for treatment-resistant/treatment-refractory forms of depression

BMC Psychiatry

Volumn 12, Issue , 2012, Pages

  Taylor, David ^b   Carlyle, Jo anne ^b,d   McPherson, Susan ^c   Rost, Felicitas ^b   Thomas, Rachel ^b   Fonagy, Peter ^a  

^a UNIVERSITY COLLEGE LONDON   (United Kingdom)

^b TAVISTOCK CLINIC   (United Kingdom)

^c UNIVERSITY OF ESSEX   (United Kingdom)

^d Hamilton House   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ARTICLE; BIPOLAR DISORDER; COMORBIDITY; CONTROLLED STUDY; COST EFFECTIVENESS ANALYSIS; DISEASE SEVERITY; HUMAN; LEARNING DISORDER; MAJOR DEPRESSION; PSYCHOANALYTIC THEORY; PSYCHODYNAMICS; PSYCHOSIS; PSYCHOSOCIAL DISORDER; PSYCHOTHERAPY; QUALITY OF LIFE; RANDOMIZED CONTROLLED TRIAL; TREATMENT OUTCOME; TREATMENT RESISTANT DEPRESSION; ADULT; CLINICAL PROTOCOL; COST BENEFIT ANALYSIS; DEPRESSIVE DISORDER, MAJOR; DEPRESSIVE DISORDER, TREATMENT-RESISTANT; FOLLOW UP; METHODOLOGY; PRIMARY HEALTH CARE; PSYCHOANALYSIS; PSYCHOLOGY; ECONOMIC EVALUATION; OUTCOMES RESEARCH; PATIENT REFERRAL; SEMI STRUCTURED INTERVIEW; TAVISTOCK PSYCHODYNAMIC INTERVIEW;

ADULT; CLINICAL PROTOCOLS; COST-BENEFIT ANALYSIS; DEPRESSIVE DISORDER, MAJOR; DEPRESSIVE DISORDER, TREATMENT-RESISTANT; FOLLOW-UP STUDIES; HUMANS; PRIMARY HEALTH CARE; PSYCHOANALYTIC THERAPY; RESEARCH DESIGN; TREATMENT OUTCOME;

EID: 84861993287     PISSN: None     EISSN: 1471244X     Source Type: Journal    
DOI: 10.1186/1471-244X-12-60     Document Type: Article

References (119)

1. Moussavi S, Chatterji S, Verdes E, Tandon A, Patel V, Ustun B. Depression, chronic diseases, and decrements in health: results from the World Health Surveys. Lancet 2007, 370(9590):851-858. 10.1016/S0140-6736(07)61415-9, 17826170.
2. Main M, Kaplan N, Cassidy J. Security in infancy, childhood, and adulthood: a move to the level of representation. Monogr Soc Res Child Dev 1985, 40(1-2):66-104.
3. Boland RJ, Keller MB, Gotlib IH, Hammen CL. Course and outcome of depression. Handbook of depression 2002, 43-60. Guilford Press, New York.
4. Stimpson N, Agrawal N, Lewis G. Randomised controlled trials investigating pharmacological and psychological interventions for treatment-refractory depression: systematic review. Br J Psychiatry 2002, 181(4):284-294. 10.1192/bjp.181.4.284, 12356654.
5. Buszewicz M, Griffin M, McMahon EM, Beecham J, King M. Evaluation of a system of structured, pro-active care for chronic depression in primary care: a randomised controlled trial. BMC Psychiatry 2010, 10:61. 10.1186/1471-244X-10-61, 2923105, 20684786.
6. Angst J, Merikangas K. The depressive spectrum: diagnostic classification and course. J Affect Disord 1997, 45(1):31-40. 10.1016/S0165-0327(97)00057-8, 9268773.
7. Scott J. Chronic depression. Br J Psychiatry 1988, 153:287-297. 10.1192/bjp.153.3.287, 3074847.
8. Lee AS, Murray RM. The long-term outcome of Maudsley depressives. Br J Psychiatry 1988, 153:741-751. 10.1192/bjp.153.6.741, 3256373.
9. Paykel ES, Scott J, Cornwall PL, Abbott R, Crane C, Pope M, et al. Duration of relapse prevention after cognitive therapy in residual depression: follow-up of controlled trial. Psychological medicine:J Res Psychiatry Allied Sci 2005, 35(1):59-68.
10. Piccinelli M, Wilkinson G. Outcome of depression in psychiatric settings. Br J Psychiatry 1994, 164:297-304. 10.1192/bjp.164.3.297, 8199782.
11. McPherson S, Cairns P, Carlyle J, Shapiro DA, Richardson P, Taylor D. The effectiveness of psychological treatments for treatment-resistant depression: a systematic review. Acta Psychiatr Scand 2005, 111(5):331-340. 10.1111/j.1600-0447.2004.00498.x, 15819726.
12. Kessler RC, Zhao S, Blazer DG, Swartz M. Prevalence, correlates, and course of minor depression and major depression in the national comorbidity survey. J Affect Disord 1997, 45(1-2):19-30.
13. Angst J, Dobler-Mikola A. The Zurich study, II. The continuum from normal to pathological depressive mood swings. Eur Arch Psychiatry Neurol Sci 1984, 234(1):21-29. 10.1007/BF00432879, 6333344.
14. Angst J, Dobler-Mikola A. The Zurich Study: VI. A continuum from depression to anxiety disorders?. Eur Arch Psychiatry Neurol Sci 1985, 235(3):179-186. 10.1007/BF00380990, 4092715.
15. Andrews G. Reducing the burden of depression. Can J Psychiatry / La Revue canadienne de psychiatrie 2008, 53(7):420-427.
16. McPherson S, Armstrong D. Negotiating 'depression' in primary care: a qualitative study. Soc Sci Med 2009, 69(8):1137-1143. 10.1016/j.socscimed.2009.05.032, 19527919.
17. Hollon SD, Ponniah K. A review of empirically supported psychological therapies for mood disorders in adults. Depress Anxiety 2010 Oct, 27(10):891-932.
18. De RM. Testimonio: on the evidence for decisions about the use of therapeutic interventions. Clin Med 2008 Dec, 8(6):579-588.
19. Bower P, Gilbody S, Richards D, Fletcher J, Sutton A. Collaborative care for depression in primary care. Making sense of a complex intervention: systematic review and meta-regression. Br J Psychiatry 2006, 189:484-493. 10.1192/bjp.bp.106.023655, 17139031.
20. Abbass AA, Hancock JT, Henderson J, Kisely SR. Short-term psychodynamic psychotherapies for common mental disorders. Cochrane Database Syst Rev 2006, 189(Issue 4):484-493. Article No. CD004687.
21. Morriss R, Marttunnen S, Garland A, Nixon N, McDonald R, Sweeney T, et al. Randomised controlled trial of the clinical and cost effectiveness of a specialist team for managing refractory unipolar depressive disorder. BMC Psychiatry 2010, 10:100. 10.1186/1471-244X-10-100, 3001706, 21114826.
22. Anderson R, New MRC. guidance on evaluating complex interventions: clarifying what interventions work by researching how and why they are effective. BMJ: Br Med J (International Edition). 2008, 337(7676):944-945.
23. Byng R. Using antidepressants in primary care: keep talking!. Healthc Couns Psychother J 2005, 5(2):14-15.
24. Craig P, Dieppe P, Macintyre S, Michie S, Nazareth I, Petticrew M. Developing and evaluating complex interventions: the new Medical Research Council guidance. BMJ 2008, 337:a1655. 10.1136/bmj.a1655, 2769032, 18824488.
25. Board MHSaPHR A framework for the development and evaluation of RCTs for complex interventions to improve health 2000, [cited; Available from, Board MHSaPHR.
26. Freud S. Mourning and Melancholia 1917, , .
27. Klein M. Mourning and its relation to manic-depressive states. Int J Psychoanal 1940, 21:125-153.
28. Taylor D. Consenting to be robbed so as not to be murdered. Psychoanal Psychother 2009, 23(3):263-275.
29. Stiles WB, Shapiro DA, Firth-Cozens JA. Therapist differences in the use of verbal response mode forms and intents. Psychotherapy: Theory Research Practice Training 1989, 26(3):314-322.
30. Gerber AJ, Kocsis JH, Milrod BL, Roose SP, Barber JP, Thase ME, et al. A quality-based review of randomized controlled trials of psychodynamic psychotherapy. Am J Psychiatry 2011 Sep 15, 168(1):19-28.
31. Leichsenring F. Comparative effects of short-term psychodynamic psychotherapy and cognitive-behavioral therapy in depression: a meta-analytic approach. Clin Psychol Rev 2001, 21(3):401-419. 10.1016/S0272-7358(99)00057-4, 11288607.
32. Fonagy P, Roth A, Higgitt A. Psychodynamic psychotherapies: evidence-based practice and clinical wisdom. Bull Menninger Clin 2005, 69(1):1-58. 10.1521/bumc.69.1.1.62267, 15899755.
33. Shedler J. The efficacy of psychodynamic psychotherapy. Am Psychol 2010, 65(2):98-109.
34. Leichsenring F, Biskup J, Kreische R, Staats H. The Göttingen study of psychoanalytic therapy: first results. Int J Psychoanal 2005, 86(2):433-455. 10.1516/XX6F-AU0W-KWM3-G6LU, 16089199.
35. Leichsenring F, Rabung S. Long-term psychodyanmic psychotherapy in complex mental disorders: update of a meta-analysis. Br J Psychiatry 2011, 199:15-22. 10.1192/bjp.bp.110.082776, 21719877.
36. Sandell R, Blomberg J, Lazar A, Carlsson J, Broberg J, Schubert J. Varieties of long-term outcome among patients in psychoanalysis and long-term psychotherapy: a review of findings in the Stockholm outcome of psychoanalysis and psychotherapy project (Stoppp). Int J Psychoanal 2000, 81(5):921-942. 10.1516/0020757001600291, 11109577.
37. Beutel M, Rasting M, Leuzinger-Bohleber M, Target M. Long-term treatments from the perspectives of the former patients. Outcomes of psychoanalytic treatment: Perspectives for therapists and researchers 2002, 130-142. Whurr Publishers, Philadelphia.
38. Milton J. Psychoanalysis and cognitive behaviour therapy-rival paradigms or common ground?. Int J Psychoanal 2001, 82(Pt 3):431-447.
39. Goldberg D. The interplay between biological and psychological factors in determining vulnerability to mental disorders. Psychoanal Psychother 2009, 23(3):236-247.
40. Hill J. Developmental perspectives on adult depression. Psychoanal Psychother 2009, 23(3):200-212.
41. Chiesa M, Fonagy P, Bateman AW, Mace C. Psychiatric morbidity and treatment pathway outcomes of patients presenting to specialist NHS psychodynamic psychotherapy services: results from a multi-centre study. Psychol Psychother 2009 Mar, 82(Pt 1):83-98.
42. Shedler J, Westen D. Dimensions of personality pathology: an alternative to the five-factor model. Am J Psychiatry 2004 Oct, 161(10):1743-1754.
43. Skodol AE, Clark LA, Bender D, Krueger RF, Morey LC, Verheul R, et al. Proposed changes in personality and personality disorder assessment and diagnosis for DSM-5 Part I: description and rationale. Pers Disord: Theory Res Treat 2011, 2:4-22.
44. Hamilton M. Development of a rating scale for primary depressive illness. Br J Soc Clin Psychol 1967, 6(4):278-296. 10.1111/j.2044-8260.1967.tb00530.x, 6080235.
45. Cuijpers P, van Straten A, Andersson G, van Oppen P. Psychotherapy for depression in adults: a meta-analysis of comparative outcome studies. J Consult Clin Psychol 2008 Dec, 76(6):909-922.
46. Bateman AW, Fonagy P. Randomized controlled trial of outpatient Mentalization-based treatment versus structured clinical management for borderline personality disorder. Am J Psychiatry 2009, 166(12):1355-1364. 10.1176/appi.ajp.2009.09040539, 19833787.
47. Statistics OfN Psychiatric Morbidity Survey 2000, ONS, London, Statistics OfN.
48. Elkin I, Shea MT, Watkins JT, Imber SD. National institute of mental health treatment of depression collaborative research program: general effectiveness of treatments. Arch Gen Psychiatry 1989, 46(11):971-982. 10.1001/archpsyc.1989.01810110013002, 2684085.
49. Taylor D. Das tavistock-manual der psychoanalytischen psychotherapie â€" Unter besonderer berÃ1-Aprcksichtigung der chronischen depression. Psyche: Zeitschrift fÃ1-Aprr Psychoanalyse und ihre Anwendungen 2010, 64(9-10):833-861.
50. Gabbard GO. Psychodynamic Psychiatry in Clinical Practice 2005, American Psychiatric Press, Arlington, 4.
51. Clarkin JF, Fonagy P, Gabbard GO. Psychodynamic psychotherapy for personality disorders: A clinical handbook 2010, American Psychiatric Publishing, Inc., Arlington.
52. Leuzinger-Bohleber M, Bahrke U. Langzeittherapie bei Chronischen Depressionen (LAC) , , [cited; Available from: http://www.sfi-frankfurt.de/forschung/forschungsfeld-2/depressionsstudie/projektbeschreibung.html.
53. Jones EE. Manual for the psychotherapy process q-set 1985, University of California, Berkeley.
54. Jones EE. Therapeutic action: a guide to psychoanalytic therapy 2000, Jason Aronson, Northvale.
55. Ablon JS, Jones EE. On analytic process. J Am Psychoanal Assoc 2005, 2:541-568. discussion 69-78.
56. Ablon JS, Jones EE. Validity of controlled clinical trials of psychotherapy: findings from the NIMH Treatment of depression collaborative research program. Am J Psychiatry 2002 May, 159(5):775-783.
57. Ablon JS, Jones EE. Psychotherapy process in the NIMH collaborative research program. J Consult Clin Psychol 1999 Feb, 67(1):64-75.
58. Jones EE, Pulos SM. Comparing the process in psychodynamic and cognitive-behavioral therapies. J Consult Clin Psychol 1993, 61(2):306-316.
59. Ablon JS, Levy RA, Katzenstein T. Beyond brand names of psychotherapy: identifying empirically supported change processes. Psychotherapy: Theory, Research, Practice, Training 2006, 43:216-231.
60. NICE NIfhace Depression. The treatment and management of depression in adults (updated version) 2010, National Collaborating Centre for Mental Health, , NICE NIfhace.
61. Beecham J, Knapp M, Thornicroft G, Brewin CR, Wing J. Costing psychiatric interventions. Measuring mental health needs 1992, 163-183. Gaskell/Royal College of Psychiatrists, London England.
62. Nezu AM, Ronan GF, Meadows EA, McClure KS. Practitioner's guide to empirically based measures of depression 2000, Kluwer Academic Publishers, Dordrecht Netherlands.
63. Bagby RM, Ryder AG, Schuller DR, Marshall MB. The hamilton depression rating scale: has the gold standard become a lead weight?. Am J Psychiatry 2004 Dec, 161(12):2163-2177.
64. Beck AT, Steer RA, Brown G. Manual for the Beck Depression Inventory-II 1996, Psychological Corporation, San Antonio TX.
65. First MB, Spitzer RL, Gibbon M, Williams JBW. User's guide for the structured clinical interview for DSM-IV-TR Axis I Disorders - Research version 2001, Biometric Research, New York State Psychiatric Institute, New York.
66. Shear MK, Greeno C, Kang J, Ludewig D, Frank E, Swartz HA, et al. Diagnosis of non-psychotic patients in community clinics. Am J Psychiatry 2000, 157(4):581-587. 10.1176/appi.ajp.157.4.581, 10739417.
67. Lobbestael J, Leurgans M, Arntz A. Inter-rater reliability of the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID I) and Axis II Disorders (SCID II). Clin Psychol Psychother 2010, 18(1):75-79.
68. First MB, Gibbon M, Spitzer RL, Williams JBW, Benjamins LS. Structured Clinical Interview for DSM-IV Axis II Personality Disorders, (SCID-II) 1997, American Psychiatric Press, Inc, Washington.
69. Farmer RF, Chapman AL. Evaluation of DSM-IV personality disorder criteria as assessed by the structured clinical interview for DSM-IV personality disorders. Compr Psychiatry 2002, 43(4):285-300. 10.1053/comp.2002.33494, 12107866.
70. Birtchnell J. Relating in psychotherapy: The application of a new theory 1999, Praeger Publishers/Greenwood Publishing Group, Westport.
71. Birtchnell J, Evans C. The Person's relating to others questionnaire (PROQ2). Pers Individ Differ 2004, 36(1):125-140.
72. Hilsenroth MJ, Ackerman SJ, Blagys MD, Baumann BD, Baity MR, Smith SR, et al. Reliability and validity of DSM-IV axis V. Am J Psychiatry 2000, 157(11):1858-1863. 10.1176/appi.ajp.157.11.1858, 11058486.
73. Evans C, Mellor-Clark J, Margison F, Barkham M, Audin K, Connell J, et al. CORE: clinical outcomes in routine evaluation. J Ment Health 2000, 9(3):247-255.
74. Evans C, Connell J, Barkham M, Margison F, McGrath G, Mellor-Clark J, et al. Towards a standardised brief outcome measure: psychometric properties and utility of the CORE-OM. Br J Psychiatry 2002, 180:51-60. 10.1192/bjp.180.1.51, 11772852.
75. Endicott J, Nee J, Harrison W, Blumenthal R. Quality of life enjoyment and satisfaction questionnaire: a new measure. Psychopharmacol Bull 1993, 29(2):321-326.
76. Schechter D, Endicott J, Nee J. Quality of life of 'normal' controls: association with lifetime history of mental illness. Psychiatry Res 2007, 152(1):45-54. 10.1016/j.psychres.2006.09.008, 2291021, 17363070.
77. White IR, Thompson SG. Adjusting for partially missing baseline measurements in randomized trials. Stat Med 2005 Apr 15, 24(7):993-1007.
78. Graham JW. Missing data analysis: making it work in the real world. Annu Rev Psychol 2009, 40:549-576.
79. Rabe-Hesketh S, Skrondal A. Multilevel and longitudinal modelling using STATA 2008, Stata Press, College Station, 2.
80. Liang KY, Zeger SL. Longitudinal data analysis using general linear models. Biometrika 1986, 73:1208-1216.
81. Mignon HS, Gamerman D. Statistical inference: An integrated approach 1999, Arnold, London.
82. Drummond M, O'Brien B, Stoddart G. Methods for the evaluation of health care programmes 1997, Oxford University Press, Oxford.
83. Ginner H, Werbart A, Levander S, Sahlberg B. Tillförlitlighet i studier av subjektiva förklaringssystem: Ett kodningssystem för privata teorier om patogenes och kur [Reliability in studies of subjective explanatory systems: A coding system for private theories of pathogenesis and cure] 2001, , .
84. Lilliengren P, Werbart A. A model of therapeutic action grounded in the patients' view of curative and hindering factors in psychoanalytic psychotherapy. Psychother: Theory, Res Pract Train 2005, 42(3):324-339.
85. Werbart A, Levander S. Understanding the incomprehensible: private theories of first-episode psychotic patients and their therapists. Bull Menninger Clin 2005, 69(2):103-136. 10.1521/bumc.69.2.103.66507, 16006248.
86. Werbart A, Levander S. Two sets of private theories in analysands and their analysts: utopian versus attainable cures. Psychoanal Psychol 2006, 23(1):108-127.
87. Kvale S. InterViews: An introduction to qualitative research interviewing 1994, Sage Publications, Inc, Thousand Oaks.
88. Carlyle J. The Tavistock Psychodynamic Interview 2002, Tavistock Clinic, London.
89. Crowell JA, Owens G. Current Relationship Interview and scoring system. Unpublished manuscript 1996, State University of New York at Stony Brook, New York.
90. Piper WE, McCallum M, Joyce AS. Manual for assessment of quality of object relations. Unpublished Manuscript 1993, University of British Columbia at Vancover, Canada.
91. Bakermans-Kranenburg MJ, van IMH. The first 10,000 Adult Attachment Interviews: distributions of adult attachment representations in clinical and non-clinical groups. Attach Hum Dev 2009, 11(3):223-263. 10.1080/14616730902814762, 19455453.
92. Main M. Discourse, prediction, and recent studies in attachment: implications for psychoanalysis. J Am Psychoanal Assoc 1993, 41S:209-244.
93. Roisman GI, Collins WA, Sroufe LA, Egeland B. Predictors of young adults' representations of and behavior in their current romantic relationship: prospective tests of the prototype hypothesis. Attach Hum Dev 2005 Jun, 7(2):105-121.
94. Rosenfeld H. An investigation into the psycho-analytic theory of depression. Int J Psychoanal 1959, 40:105-129.
95. Blatt SJ. Levels of object representation in anaclitic and introjective depression. Psychoanal Study Child 1974, 29(10):7-157.
96. Blatt SJ, Maroudas C. Convergences among psychoanalytic and cognitive: behavioral theories of depression. Psychoanal Psychol 1992, 9(2):157-190.
97. Bleichmar HB. Some subtypes of depression and their implications for psychoanalytic treatment. Int J Psychoanal 1996, 77:935-961.
98. Taylor D. Klinische Probleme chronischer, refraktaere oder behandlungsresistenter depression. Psyche: Zeitschrift fuer Psychoanalyse und ihre Anwendungen 2005, 59:843-863.
99. Taylor D, Harris N. Developing a psycho-analytic typology of depression 2005, , .
100. Pope C, Mays N. Qualitative research in health care 2006, Blackwell Publishing BMJ Books, Malden Williston, 3.
101. Barbour RS. Checklists for improving rigour in qualitative research: a case of the tail wagging the dog?. BMJ: Br Med J (International Edition) 2001, 322(7294):1115-1117.
102. Seitz PFD. The consensus problem in psychoanalytic research. Methods of research in psychotherapy 1966, 209-225. Appleton-Century-Croft, New York, Auerbach LGaA.
103. Leuzinger-Bohleber M, Target M. Outcomes of psychoanalytic treatment: Perspectives for therapists and researchers 2002, Whurr Publishers, Philadelphia.
104. Emirbayer M, Mische A. What is agency?. Am J Sociol 1998, 103(4):962-1023.
105. Jurado M, Rosselli M. The elusive nature of executive functions: a review of our current understanding. Neuropsychol Rev 2007, 17(3):213-233. 10.1007/s11065-007-9040-z, 17786559.
106. Allen JG, Munich RL, Rogan A. Agency in illness and recovery 2005, [cited; Available from.
107. Bandura A. Self-efficacy in changing societies 1995, Cambridge University Press, New York.
108. Evans K. Taking control of their lives? Agency in young adult transitions in England and the new Germany. J Youth Stud 2002, 5(3):245-268.
109. Laplanche J, Pontalis JB. The language of psycho-analysis. (Trans. Donald Nicholson-Smith) 1973, W. W. Norton, Oxford England.
110. Schafer R. On the theoretical and technical conceptualization of activity and passivity. Psychoanal Q 1968, 37(2):173-198.
111. Knekt P, Laaksonen MA, Raitasalo R, Haaramo P, Lindfors O. Changes in lifestyle for psychiatric patients three years after the start of short- and long-term psychodynamic psychotherapy and solution-focused therapy. Eur Psychiatry 2010 Jan, 25(1):1-7.
112. A randomized trial of the effects of four forms of psychotherapy on depressive and anxiety disorders: Design methods and results on the effectiveness of short term psychodynamic psychotherapy and solution focused therapy during a 1-year follow-up 2004, Social Insurance Institution, Helsinki, Knekt P, Lindfors O.
113. Knekt P, Lindfors O, Laaksonen MA. Review: long term psychodynamic psychotherapy improves outcomes in people with complex mental disorders. Evid Based Ment Health 2009 May, 12(2):56.
114. Knekt P, Lindfors O, Laaksonen MA, Renlund C, Haaramo P, Harkanen T, et al. Quasi-experimental study on the effectiveness of psychoanalysis, long-term and short-term psychotherapy on psychiatric symptoms, work ability and functional capacity during a 5-year follow-up. J Affect Disord 2011 Feb 11, 132(1-2):37-47.
115. World Health Organisation World Health Report 2001: mental health: new understanding, new hope 2001, WHO, Geneva, World Health Organisation.
116. Mukherjee S. The emperor of all maladies 2011, Scribner, New York.
117. Wolpert L, Fonagy P. There is no place for the psychoanalytic case report in the British Journal of Psychiatry. Br J Psychiatry 2009 Dec, 195(6):483-487.
118. Thase ME, Nolen WA, Zohar J, Roose SP, Amsterdam JD. The roles of psychosocial factors and psychotherapy in refractory depression. Missing pieces in the puzzle of treatment resistance? Refractory depression: Current strategies and future directions 1994, 83-95. John Wiley & Sons, Oxford England.
119. Sedgwick P. Sources of bias in randomised controlled trials II. MBJ 2010, 341:c7053.