1. Health-care interactions and placebo effects:
A systematic review
Zelda Di Blasi, PhD; University of California San Francisco; Elaine Harkness, PhD, Edzard Ernst, MD
University of Exeter (UK); Jos Kleijnen, MD, PhD, University of York (UK)
Background
Methods
Results
23,645
Bibliographic citation reviewed
Study design:
• We conducted a systematic review searching
11 medical, psychological, and nursing
databases from their origin, using 187 search terms.
• Two investigators (ZDB, EH) independently
examined the abstract of candidate articles.
• We included only randomized clinical trials that
focused on health care interactions and measured
a physical health outcome. We excluded studies of
healthy volunteers or psychiatric population, and
complex psychosocial interventions.
• We then abstracted information on the
methodological quality, study design,
outcomes measured, and clinical population of
each study.
Can good doctor-patient
relationships have a therapeutic
effect irrespective of any specific
medical intervention?
We hypothesized that along with
Physical Care (e.g. drugs, surgery),
and Behavioral Care (e.g. advice on
healthy lifestyle changes), practitioners
can alter patient’s health through:
 Cognitive Care: by
influencing patients’ beliefs and
expectations (e.g. about the effects of
treatment or about their illness).
 Emotional Care: by lowering
unhelpful emotions such as fear or
anxiety, by being supportive, empathic,
and warm.
Articles reviewed in full
624
Articles included in the analysis 25
• Studies were average to poor in quality.
• Half of the 19 studies examining the effects
of expectations on health found positive effects.
• A combination of emotional and cognitive
care was found to produce the most
consistent effect.
Conclusions
• There are few rigorous trials examining the effects of health care interactions. • The heterogeneity of types of interventions and outcomes measured make it difficult to examine trends. • There is some evidence to suggest that a combination of cognitive and emotional care is more effective than cognitive care alone Funded by the Fetzer Institute (USA) Published in the Lancet
Objective
To review whether there is any empirical
evidence to suggest that practitioners
can influence patients’ recovery or
improvement from illness through
their interactions.