1
Chinese herbal medicine: developing evidence
relevant to current practice
Hugh MacPherson
Senior Research FellowDepartment of Health Sciences
DEPARTMENT OF HEALTH SCIENCES
Where do we start?…….. a quote
“A depressed patient who takes St John’s wort and comes out of depression arguably gathers enough strength to commit suicide, so it is dangerous” Ernst (Guardian 4th Oct 2007)
DEPARTMENT OF HEALTH SCIENCES
Another quote……
“Today there is not a shred of scientific evidence that traditional herbalists do more good than harm.”Ernst (Post Grad Med Journal Oct 2007)
DEPARTMENT OF HEALTH SCIENCES
BIQ QUESTIONS …..
How do we translate the results we see in clinic practice into evidence!!!!
How do we show how safe we are???
DEPARTMENT OF HEALTH SCIENCES
Establishing evidence for a new drug
Screening
Mechanism
Efficacy RCT
Effectiveness RCT
Safety
DEPARTMENT OF HEALTH SCIENCES
Why use the Randomised Controlled Trial, the (RCT)?
Key reasons are:
Control for natural history of the disease (people tend to recover anyway)
Attribute change to interventionMinimise bias
DEPARTMENT OF HEALTH SCIENCES
Two types of RCT:which depend on the research question
Explanatory RCTs answer the question: “is there a herbal component that has an effect per se?”
(for component efficacy, we need a placebo comparison)
Pragmatic RCTs answer the question: “is there an effect of herbal medicine as a package?”
(for system effectiveness, we need a real world comparison)
DEPARTMENT OF HEALTH SCIENCES
Explanatory and pragmatic RCTs
real world comparisonplacebo controlledchronic conditionsacute conditionsroutine practiceexperimental contextEffectiveness overallEfficacy of components
high external validityhigh internal validityindividualised Trstandardised Tr
Pragmatic RCTExplanatory RCT
DEPARTMENT OF HEALTH SCIENCES
Question: how do we conceptualise herbal medicine?
A simple intervention:Single herbs prescribed by symptomLimited or no theory
A complex intervention:Multiple herbsSynergistic interactionsInformed by theory
DEPARTMENT OF HEALTH SCIENCES
TOTAL ACTUALBENEFIT
BENEFIT DUE TO SPECIFIC
HERBS
BENEFIT DUE TO INTERACTIONS AND PROCESSES
BENEFIT DUE TO
PLACEBO
HERBAL MEDICINE AS COMPLEXINTERVENTION
DEPARTMENT OF HEALTH SCIENCES
New drug(release process)
Screening
Mechanism
Component efficacy
System effectiveness
Safety
Utilisation
Safety
System effectiveness
Component efficacy
Mechanism
Chinese herbs(in widespread use)
DEPARTMENT OF HEALTH SCIENCES
Safety of routine practice?
The Australian data – retrospective practitioner survey conducted in 1996*1100 practitioners participatedFindings: one adverse event per 9 months, commonly:
Gastrointestinal symptomsSkin reactionsSevere fatigue
* Bensoussan & Myers 1996
DEPARTMENT OF HEALTH SCIENCES
Safety of routine practice in UK?
Research question:
“What adverse events are associated with
routine practice of Chinese herbal medicine
in the UK when prescribed by RCHM
members?”
MacPherson H, Liu B. "The safety of Chinese herbal medicine: a pilot for a national survey." Journal of Complementary & Alternative Medicine. 2005; 11(4): 617-626.
DEPARTMENT OF HEALTH SCIENCES
Research methods
Longitudinal study over 1 month
549 RCHM practitioners invited
71 participated (13%) – asked to hand out survey forms to 10 patients
48% practitioners are female average 10 years in practiceaverage treated 10 herbs patients a week
DEPARTMENT OF HEALTH SCIENCES
Who are our patients?
78% femaleMean age 45 yrs44% had symptoms > 5 years84% had seen GP about condition
DEPARTMENT OF HEALTH SCIENCES
Four week follow-up …..
144 patients responded (20% of max)70% consulted more than once in 4 weeks74% took herbs all 4 weeksNot recorded:
DiagnosisPrescriptionsIndividual herbsMedication
DEPARTMENT OF HEALTH SCIENCES
What type of herbal preparation?
38% herb powder27% raw herb decoction23% tablet4% tincture
DEPARTMENT OF HEALTH SCIENCES
Commonly reported reasons for consulting:
15% gynaecology12% skin conditions12% digestive related12% general health10% psychological
DEPARTMENT OF HEALTH SCIENCES
Adverse events at four weeks
32 20 patients
Total eventsReported by
12Other3Headache 4Abdominal pain4Nausea4Fatigue6Diarrhoea
Number of events
DEPARTMENT OF HEALTH SCIENCES
Attribution of the events to the herbs
Of the 20 who experienced events: 11 patients said event(s) definitely or probably associated with herbs
For all 8 patients who reported discontinuing herbs, the symptoms recededFor all 4 who reported restarting taking the herbs, the symptoms returned
DEPARTMENT OF HEALTH SCIENCES
Tolerance of events
Regarding adverse event: 2 said “extremely bothersome” 4 said “very bothersome” 7 said “bothersome”
16 out of 20 patients would be willing to have Chinese herbal medicine again
DEPARTMENT OF HEALTH SCIENCES
What factors might be possible risk factors?
Practitioner factorsGender
Patient risk factorsGenderGP contact before surveyGP contact during 4 weeksNumber of herb consultations during 4 weeksFirst consultation with herbal practitioner (p=0.02)
DEPARTMENT OF HEALTH SCIENCES
Limitations 1: poor response rate
13% of RCHM members participated(71 out of 549)
20% of possible maximum number of patients participated (144 out of 710)(2 per practitioner)
DEPARTMENT OF HEALTH SCIENCES
Explanations (from 90 practitioners) for non participation
29% “too busy”26% “not in practice”17% “away”14% “too few patients”
DEPARTMENT OF HEALTH SCIENCES
Limitations 2: Difficulties with interpretation
Precise herbs & preparations used not knownHerb prescriptions not known
Herb-herb interactions?
Conventional medication not knownHerb-drug interactions?
DEPARTMENT OF HEALTH SCIENCES
Limitations 3: reporting bias from those who did respond
Possible under-reporting:Patients not attributing event to herbs?Patients wanting to “protect” practitioner?
Possible over-reporting:Patients incorrectly attributing event to herbs?Check lists associated with higher response rates?
DEPARTMENT OF HEALTH SCIENCES
Limitations 4: sample size too small
Large numbers are needed to know the incidence of serious adverse events
What is a serious adverse event?HospitalisationLife-threatening
DEPARTMENT OF HEALTH SCIENCES
Limitations 5: practitioner errors of omission/commission not addressed
OmissionMissing serious pathologyMissing serious side effects of herbs
Commission Inappropriate advice about medication
DEPARTMENT OF HEALTH SCIENCES
Strengths of study - 1
First study to identify the patient perspective on safety
Patient reports are more reliable than practitioner reports
DEPARTMENT OF HEALTH SCIENCES
Comparing patient reports with practitioner reports for herbal medicine
1 event per 2 months(32 events/71 practitioners/month)
1 event per 9 months
Adverse event rate per practitioner
144 patients in UK
1100 practitioners in Australia
Who reported events
Patient studyPractitioner study
DEPARTMENT OF HEALTH SCIENCES
Strengths of study - 2
Methodology has been tested with acupuncture: two studies with practitioners and patients reporting:
British Medical Journal 2001; 323: 486-487
Quality & Safety in Health Care. 2004; 13: 349-355
DEPARTMENT OF HEALTH SCIENCES
Acupuncture safety study - 1
Practitioner study - one month data collecting574 BAcC acupuncturists reported Covered 34,000 consultations No serious adverse events43 minor adverse events
BMJ editorial: “Acupuncture is safe in competent hands”. [Charles Vincent BMJ 2001:323:467-8]
DEPARTMENT OF HEALTH SCIENCES
Acupuncture safety studies - 2
Patient study – 3 months data collecting from 638 BAcC acupuncturists
6348 patients reported that over 3 months no serious adverse events 1044 minor events omission/commission: 2 cases of missed diagnosis or delayed
treatment – none serious 6 cases of advice about medication reduction caused reactions – caused return of prior symptoms
DEPARTMENT OF HEALTH SCIENCES
Acupuncture vs. Chinese herbal medicine – comparing conditions
•Musculo-skeletal•Depression•Eczema•Chronic pain•IBS
•Gyn•Skin•Digestive•General•Psychological
•Musculo-skeletal•Psychological•General•Neurological
Common conditions
Effectiveness gaps in primary care [Fisher 2004]
Chinese herbs patients
Acupuncture patient(Study 2)
DEPARTMENT OF HEALTH SCIENCES
Acupuncture vs. herbal medicine – comparing type of adverse events
•Diarrhoea •Fatigue•Nausea•Abdominal pain•Headache
•Tiredness•Pain on needling•Dizziness•Headache
Common adverse events
Chinese herbs patients
Acupuncture patients(Study 2)
DEPARTMENT OF HEALTH SCIENCES
Acupuncture vs. Chinese herbal medicine – comparing event rate
0.5 events per month
0.5 eventsper month
0.1 events per month
Event rate per practitioner
RCHM patients
BAcC patients
BAcC practitioners
Who reported
Chinese herbs patientstudy
Acupuncture patient study(Study 2)
Acupuncture practitioner study (Study 1)
DEPARTMENT OF HEALTH SCIENCES
Future strategies 1 – replicating this research as full-scale study?
Funding requiredOpportunity to establish more robust data
Large sample size Better response rate….
DEPARTMENT OF HEALTH SCIENCES
Comparing practitioner response rates
13% 31% 33%Response rate of practitioners
Chinese herb patients study
(RCHM)
Acupuncture patient study
(BAcC)
Acupuncture practitioner
study (BAcC)
DEPARTMENT OF HEALTH SCIENCES
Future strategies 2 – other options
Case control studyFollow over time “cases” (patients) who receive same herb(s), along with matched patients who do notBUT – not feasible with individualised multiple herbs
Yellow card schemeVolunteer monitoring nationallyReputation for under-reporting
DEPARTMENT OF HEALTH SCIENCES
Conclusions:
We now know the commonest adverse events The adverse event rate is higher than for acupunctureMost people are willing to continue in spite of adverse eventsPatients consulting for the first time are most likely to experience an adverse event
DEPARTMENT OF HEALTH SCIENCES
Strategies for appropriate evaluation
real-world designs:
pragmatic RCTs for effectiveness cost-effectiveness longer-term outcomes qualitative research
large scale surveys for safety
DEPARTMENT OF HEALTH SCIENCES
What to do about research?
Herbalists need to engage in researchHelp design studies and trialsProvide data on herbal medicine that is representative of practiceBuild a relevant evidence base
DEPARTMENT OF HEALTH SCIENCES
Acknowledgments for herb study
Patients and practitionersBin LiuAdvisors
Trevor SheldonTrina WardJeremy Miles
FundersRCHMUniversity of York
Top Related