Co-intervention bias

Knowledge of which treatments have been received by which study participants can affect adherence to assigned treatments and result in the biased use of other treatments (co-interventions). These biases can be reduced by using placebos to conceal the identities of the treatments being compared.

15 RECORDS
7 ARTICLES

The need to address treatment uncertainties

Principles of Testing

Treatment comparisons are essential

Treatment comparisons must be fair

Biases

Double dummy

The play of chance

Bringing it all together for the benefit of patients and the public

James Lind Library
Illustrating the development of fair tests of treatments in health care

Co-intervention bias

Knowledge of which treatments have been received by which study participants can affect adherence to assigned treatments and result in the biased use of other treatments (co-interventions). These biases can be reduced by using placebos to conceal the identities of the treatments being compared.

15 RECORDS

7 ARTICLES

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James Lind LibraryIllustrating the development of fair tests of treatments in health care

Co-intervention bias

Knowledge of which treatments have been received by which study participants can affect adherence to assigned treatments and result in the biased use of other treatments (co-interventions). These biases can be reduced by using placebos to conceal the identities of the treatments being compared.

SORT date ▲ author

15 RECORDS

7 ARTICLES

Bell JA (1941) Pertussis prophylaxis with two doses of alum-precipitated vaccine. Public Health Reports 56:1535-1546.

Plummer N, Liebmann J, Solomon S, Kammerer WH, Kalkstein M, Ensworth HK (1941) Chemotherapy versus combined chemotherapy and serum. JAMA 116:2366-2371.

Bell JA (1948) Pertussis immunization use of two doses of an alum-precipitated mixture of diphtheria toxoid and pertussis vaccine. JAMA 137:1276-1281.

Bell JA (1948) Diphtheria immunization use of an alum-precipitated mixture of pertussis vaccine and diphtheria toxoid. JAMA 137:1009-1016.

Armitage P (1960) The construction of comparable groups. In: Hill AB. Controlled clinical trials. Oxford: Oxford University Press, pp 14-18.

Hill AB (1961) Differential exclusions. In: Hill AB. Principles of medical statistics, 7th edition, pp 258-9.

Campbell DT, Stanley JC (1963) Experimental and quasi-experimental designs for research. Chicago: Rand McNally & Company.

Mainland D (1963) Elementary medical statistics: 2nd edn. Philadelphia: WB Saunders Co.

Coronary Drug Project Research Group (1980) Influence of adherence to treatment and response of cholesterol on mortality in the coronary drug project. New England Journal of Medicine 303:1038-41.

Peto J, Eden OB, Lilleyman J, Richards S (1986) Improvement in treatments for children with acute lymphoblastic leukaemia: The Medical Research Council UKALL Trials, 1972-84. Lancet 1:408-411.

Davidson I, Hillier VF (2002) Comparison of four methods of allocation for clinical trials with small sample sizes. Physiotherapy 88;12:722-729, ISSN 0031-9406.

Simpson SH, Eurich DT, Majumdar SR, Padwal RS, T Tsuyuki RT, Varney J, Johnson JA (2006) A meta-analysis of the association between adherence to drug therapy and mortality. BMJ 2006;333;15;doi:10.1136/bmj.38875.675486.55.

Wartolowska K, Judge A, Hopewell S, Collins GS, Dean BJF, Rombach I, Brindley D, Savulescu J, Beard DJ, Carr AJ (2014) Use of placebo controls in the evaluation of surgery: systematic review. BMJ 348:g3253. doi: 10.1136/bmj.g3253.

Show ALL ARTICLES Brief histories Commentaries Biographies Personal reflections Doctoral theses

Marks HM† (2006).The Kendrick-Eldering-(Frost) pertussis vaccine field trial. JLL Bulletin: Commentaries on the history of treatment evaluation.

Furberg CD (2009).How should one analyse and interpret clinical trials in which patients don’t take the treatments assigned to them? JLL Bulletin: Commentaries on the history of treatment evaluation.

Chalmers I (2010).Joseph Asbury Bell and the birth of randomized trials. JLL Bulletin: Commentaries on the history of treatment evaluation.

Peto J (2016).Reflections on the importance of strict adherence to treatment protocols: acute lymphoblastic leukaemia in children in the 1970s in the US and the UK. JLL Bulletin: Commentaries on the history of treatment evaluation.

Zwarenstein M (2016).‘Pragmatic’ and ‘Explanatory’ attitudes to randomized trials. JLL Bulletin: Commentaries on the history of treatment evaluation.

Chalmers I, Matthews R, Glasziou P, Boutron I, Armitage P† (2023).Analysis of clinical trial by Treatment Allocated or by Treatment Received? Applying ‘the intention-to-treat principle’. JLL Bulletin: Commentaries on the history of treatment evaluation.

Glasziou P, Matthews R, Boutron I, Chalmers I, Armitage P† (2023)The differences and overlaps between ‘explanatory’ and ‘pragmatic’ controlled trials: a historical perspective. JLL Bulletin: Commentaries on the history of treatment evaluation.

Topics

BROWSE

ABOUT

COPYRIGHT

FEEDBACK

James Lind Library
Illustrating the development of fair tests of treatments in health care

Bell JA (1941)
Pertussis prophylaxis with two doses of alum-precipitated vaccine. Public Health Reports 56:1535-1546.

Plummer N, Liebmann J, Solomon S, Kammerer WH, Kalkstein M, Ensworth HK (1941)
Chemotherapy versus combined chemotherapy and serum. JAMA 116:2366-2371.

Bell JA (1948)
Pertussis immunization use of two doses of an alum-precipitated mixture of diphtheria toxoid and pertussis vaccine. JAMA 137:1276-1281.

Bell JA (1948)
Diphtheria immunization use of an alum-precipitated mixture of pertussis vaccine and diphtheria toxoid. JAMA 137:1009-1016.

Armitage P (1960)
The construction of comparable groups. In: Hill AB. Controlled clinical trials. Oxford: Oxford University Press, pp 14-18.

Hill AB (1961)
Differential exclusions. In: Hill AB. Principles of medical statistics, 7th edition, pp 258-9.

Campbell DT, Stanley JC (1963)
Experimental and quasi-experimental designs for research. Chicago: Rand McNally & Company.

Mainland D (1963)
Elementary medical statistics: 2nd edn. Philadelphia: WB Saunders Co.

Coronary Drug Project Research Group (1980)
Influence of adherence to treatment and response of cholesterol on mortality in the coronary drug project. New England Journal of Medicine 303:1038-41.

Peto J, Eden OB, Lilleyman J, Richards S (1986)
Improvement in treatments for children with acute lymphoblastic leukaemia: The Medical Research Council UKALL Trials, 1972-84. Lancet 1:408-411.

Davidson I, Hillier VF (2002)
Comparison of four methods of allocation for clinical trials with small sample sizes. Physiotherapy 88;12:722-729, ISSN 0031-9406.

Simpson SH, Eurich DT, Majumdar SR, Padwal RS, T Tsuyuki RT, Varney J, Johnson JA (2006)
A meta-analysis of the association between adherence to drug therapy and mortality. BMJ 2006;333;15;doi:10.1136/bmj.38875.675486.55.

Wartolowska K, Judge A, Hopewell S, Collins GS, Dean BJF, Rombach I, Brindley D, Savulescu J, Beard DJ, Carr AJ (2014)
Use of placebo controls in the evaluation of surgery: systematic review. BMJ 348:g3253. doi: 10.1136/bmj.g3253.

Show

Marks HM† (2006).
The Kendrick-Eldering-(Frost) pertussis vaccine field trial. JLL Bulletin: Commentaries on the history of treatment evaluation.

Furberg CD (2009).
How should one analyse and interpret clinical trials in which patients don’t take the treatments assigned to them? JLL Bulletin: Commentaries on the history of treatment evaluation.

Chalmers I (2010).
Joseph Asbury Bell and the birth of randomized trials. JLL Bulletin: Commentaries on the history of treatment evaluation.

Peto J (2016).
Reflections on the importance of strict adherence to treatment protocols: acute lymphoblastic leukaemia in children in the 1970s in the US and the UK. JLL Bulletin: Commentaries on the history of treatment evaluation.

Zwarenstein M (2016).
‘Pragmatic’ and ‘Explanatory’ attitudes to randomized trials. JLL Bulletin: Commentaries on the history of treatment evaluation.

Chalmers I, Matthews R, Glasziou P, Boutron I, Armitage P† (2023).
Analysis of clinical trial by Treatment Allocated or by Treatment Received? Applying ‘the intention-to-treat principle’. JLL Bulletin: Commentaries on the history of treatment evaluation.

Glasziou P, Matthews R, Boutron I, Chalmers I, Armitage P† (2023)
The differences and overlaps between ‘explanatory’ and ‘pragmatic’ controlled trials: a historical perspective. JLL Bulletin: Commentaries on the history of treatment evaluation.