Placebo Effects and Research in Alternative and Conventional Medicine

Abstract The placebo effect is a very powerful and unpredictable aspect of any medical treatment. Assuch, it dramatically complicates efforts at convincingly demonstrating the effectiveness of specitic effects inmedicine, conventional or alternative. This review provides a tlieoretical overview of tlie placebo effect toassist researchers in designing trials, controlled or otliereise, so that more convincing demoiistrations of spe-cific effects can be achieved.

Systematic review: The placebo effect of psychological interventions in the treatment of irritable bowel syndrome

AIM To determine the placebo response rate associated with different types of placebo interventions used in psychological intervention studies for irritable bowel syndrome. METHODS Randomized controlled trials comparing psychological interventions(stress management/relaxation therapy(cognitive) behavioral therapy, short-term psychodynamic therapy, and hypnotherapy) for the treatment of adult patients with irritable bowel syndrome(IBS) diagnosed with the Manning or Rome criteria with an adequate placebo control treatment and reporting data on IBS symptom severity were identified by searching Pub Med, Embase, the Cochrane Library, CINAHL and Psyc INFO databases. Full-text articles that were written in English and published between 1966 and February 2016 in peer-reviewed journals were selected for the present review. Placebo interventions were considered to be adequate if the number of sessions and the amount of time spent with the therapist were the same as in the active treatment. The placebo response rate(PRR) was computed for IBS symptom severity(primary outcome measure) as well as for anxiety, depression and quality of life(secondary outcome measures). RESULTS Six studies, with a total of 555 patients met the inclusion criteria. Four studies used an educational intervention, whereas two studies used a form of supportive therapy as the placebo intervention. The PRR for IBS symptom severity ranged from 25% to 59%, with a pooled mean of 41.4%. The relative PRR for the secondary outcome measures ranged from 0% to 267% for anxiety, 6% to 52% for depression 20% to 125% for quality of life. The PRR associated with pharmacological treatments, treatment with dietary bran and complementary medicine ranged from 37.5% to 47%. Contrary to our expectations, the PRR in studies on psychological interventions was comparable to that in studies on pharmacological, dietary and alternative medical interventions.CONCLUSION The PRR is probably determined to a larger extent by patient-related factors, such as expectations and desire for the treatment to be effective, than the content of the placebo intervention.

Placebo effect in the treatment of non-small cell lung cancer:a meta-analysis

Objective:The majority of non-small cell lung cancer(NSCLC)cases remain undiagnosed until advanced stages of the disease.Accumulating studies have highlighted the utility of palliative care as an effective treatment option,which relieves patients’suffering by activating placebo effect in the body.To evaluate the clinical significance of palliative care,data from NSCLC drug-randomized controlled trials(RCTs)were collected and the effects of placebo treatment examined.Methods:PubMed(MEDLINE),Scopus,Web of Science,and China National Knowledge Infrastructure databases were searched from January 1,1978 to September 1,2020.Placebo-controlled phase II/III pharmaceutical RCTs enrolling patients with solely stage III/IV NSCLC were included.The quality of included studies was assessed using the Jadad method.Single-arm and two-arm meta-analyses of the therapeutic and adverse effects of placebo,that is,the primary and secondary outcome measures,were subsequently performed using either Bayesian or conventional models.Results:Five RCTs including 2245 drug-treated and 1510 placebo-treated patients at NSCLC stage III or IV were included for the study.Low risk of bias was observed for all five included studies using the Cochrane method.Following placebo treatment,controlled disease rate of 24.1%(95%credible interval[CrI],-0.126-0.609)and dropout rate of 2.1%(95%CrI,0.007-0.039)were calculated,with a dose reduction rate of 3.0%(95%CrI,0.017-0.045).Compared with active drug treatment,the placebo treatment group had a risk ratio of 0.81(95%confidence interval,0.68-0.97)and 0.85(95%confidence interval,0.76-0.96)for the achievement of progression-free survival and overall survival,respectively.Conclusion:In NSCLC drug RCTs,placebo treatment is indicated to generally induce low toxicity in patients by dropout and dose reduction rates and adverse events,although the therapeutic responses could not be precisely determined.The results suggest that under specific circumstances,palliative care which can activate placebo effect may have similar effects as active drugs(such as erlotinib,vandetanib,or pemetrexed)in terms of prolonging survival time.