Transcript Disease Causal Chains

Conventional Classification of diseases
Let us see conventionally how the diseases are classified:
Infectious diseases
Genetic diseases
Nutritional diseases
Endocrine diseases
Mind diseases etc.
Examples of Snags in Disease Classification
Infectious Disease is not a Nutritional Disease
Nutritional Disease is not an Endocrine Disease
Each disease is being attributed to one cause etc
This creates lot of problems
Reality
It is seen sometimes that
Certain hormones reverse viral encephalitis
Let us hypothesize that
Viral encephalitis is due to endocrine problem
+ viral infection
Viral Encephalitis hypothesis
At least one of the factor creating endocrine problem
(genetic, drug, malnutrition, stress, improper lifestyle etc)
+
One of the viral infection (West Nile virus or Japanese
Encephalitis Virus or Herpes Simplex Virus or
Chandipura Virus or Measles or Mumps or Chicken pox
or Rubella or Cytomegalovirus or HIV etc)
Solution to the disease
If endocrine disorder precedes viral infection then
Rectifying endocrine disorder would prevent
encephalitis due to all viruses,
Hypothetical solution could be preventing stress,
fortified foods, sunbath or eating hypoglycaemic foods
Simple solution but complicated research
Normal Delivery
Alternative approach
Several vaccines to prevent viral encephalitis
And for each viral vaccine
Scientists may perform several studies
Yet results could be disappointing
Simple research but complicated solution
Caesarian
Prevention is better than cure
Certain diseases make patient vulnerable
Preventing the disease through vaccine for a
specific disease
Means
Preventing the specific disease
As well as
Preventing several front-end events
Prenatal preventive steps to avoid adult disease
Metabolic imprinting and programming
Prenatal and early postnatal development
can affect susceptibility to various adultonset chronic diseases
http://history.enotes.com/food-encyclopedia/metabolicimprinting-programming
Hunt for panacea
It is one of the objective of
Disease Informatics
Priors and posteriors
Health policy can not be full-proof
Unless Priors and Posteriors
Are estimated
Appropriate Health policy document
can not be prepared unless
Disease Informatics shapes well
Disease denominator
Quite a low incidence rate of a particular disease is
result of the big denominator
Why big denominator?
The disease causative agent is not considered as a
component.
It is assumed that it is the whole story
Diseases are really complex
http://www.wordinfo.info/words/index/info/view_unit/1/?letter=B&spage=3
Component  Sufficient
Component to which
Population exposed is
Part of sufficient causal mechanism
Prof. Kenneth Rothman
Button is not sufficient cause to switch on or switch off the light.
Sufficient causal mechanisms.> 1
Sufficient causal mechanisms could be more than 1
Component investigated may not share all mechanisms
By Kenneth J. Rothman and Sander Greenland
Prof. Sander Greenland
Three sufficient causes of disease.
No wiring no switching on of bulb
Encephalitis associated with viruses
(Bulb lights)
Occurs in those individuals
Who are predisposed (wiring is
completed)
And one of the several viruses (button)
Triggers the disease (Switch on the bulb)
Why newer viruses emerge?
Examine priors
Viruses can not emerge outside the host
Antioxidant deficiency in host could lead to emergence of
new viruses
Dr. Melinda Beck
http://www.jacn.org/cgi/content/abstract/20/suppl_5/384S
Disease Definition
The disease definitions require set of
intersection of some factors (component causes)
as denominators to
make the definition complete
What is seen in viral encephalitis?
Most of the encephalitic diseases attributed to viruses
Have low incidence because
Virus is not enough to cause the disease
But it may be required
In South Africa a large outbreak of west Nile affected an
estimated 18 000 people of all ages, yet only one case of
encephalitis was reported.
http://bmj.bmjjournals.com/cgi/content/full/326/7394/865
Component and sufficient causes
Which component causes come together (?)
To make sufficient causal mechanism for disease (?)
This is the challenge in Spatial Epidemiology and
For the Disease Informatics Groups
Requirement of team effort
Define complex diseases thereby
Identifying all the targets to combat disease and
Design a holistic solution
Disease features
The disease as it is understood today has
Shared + Variable features
Conventional disease definition
The universally shared features as against spatiality are
generally considered for diseases definition, however
the most optimum solutions are spatiality dependent
shared by local people than universal
Communicable diseases
In case of communicable diseases
The conventional approaches to have the
definition of disease in 3 phases
Suspected, Probable and Confirmed and
Arriving at a single cause (!!!)
Why modern approach?
Conventional approach has
Yet to generate feasible solutions for
Most of the real life health problems
Rigid Disease Definitions
One cause- one effect
It is like expecting honesty from an
individual
Who has undergone a forced
marriage
Where lies the solution?
Considering simultaneously
The non-communicable components of the disease
Could really change this picture and
Help in designing the health strategy
Multiple morbidities
Sufficient cause approach could be
fruitfully used if role of multiple
morbidities in the outcome is
precisely recognized
Components working together
It is not A + B
It is A + B + AB
An interaction can override any main effects
When there is an interaction along with main
effects, we must reexamine the main effects to see
if they are really worth paying attention to.
Famous statistician Keppel quoted by M. Plonsky
Factors working together
Statistical interaction is a property of
which linear model the researcher
selects, not a property of the population,
risk factors, or outcome.
http://ajp.psychiatryonline.org/cgi/content/full/158/6/848
Defining the diseases
The purposes of defining the
diseases are
To understand exactly what those
are
So that those are prevented or
reversed
The basis of Disease Informatics
To operate on the fact that
“Most outcomes — whether
disease or death — are caused by
A chain or web consisting of many
component causes”
This has been denoted as Disease
Causal Chain (DiCC)
Modern Epidemiology
Epidemiologists Rothman and
Greenland emphasize that the
"One cause − one effect"
understanding is
A simplistic misbelief
Baseline for Disease Informatics
“Existence of chain or web consisting
of many component causes”
Connotes lot of information and
Could be difficult to handle manually
Here goes the role of information
scientists
Gurus
Drs. Abhay and Rani Bang and their colleagues have
Successfully provided solutions to several health problems
By performing on multiple morbidities
Dr. Abhay Bang of Gadchiroli
Approach
After identifying several causes of
an infant death and having realized
that prevention of any cause could
have saved the infant, Abhay and
Rani Bang started working to solve
the riddle.
Gadchiroli
The Gadchiroli approach could be fruitfully used if
Role of multiple morbidities as pointed out by
Drs. Bangs and their colleagues
in the outcome is precisely recognized
Dr. Rani Bang
www.ashoka.org
www.indianngos.com/districts/gadchiroli.htm
Bayesian again
To tackle the problem of Multiple morbidities
Multiple hypotheses are required
Alternatively,
Disease Complex needs to be defined
Rather than several simple diseases
Disease burden
Burden of several diseases
rely on
Certain backend events of
Disease Causal Chain
Backend vs. Frontend measures
Frontend event measures are like
Pruning the branches of disease tree while
Backend event measures uproot the tree
Disease Causal Chains
The Disease Causal Chains should
be studied as
A spatial epidemiological problem
for
All the diseases together
Present in the locality.
Solving problem of Disease Complex
Disease Causal Chain
It could be developed as powerful technique
To handle disease complex
Target identification
Disease Causal Chain displays
Several targets to solve health
problem
And not just the one
Antiviral Investigation
HTS antiviral assays on New
Chemical Entities
These assays does not nullify
The traditionally established
utility of certain formulations
What is neglected?
The ability of
Traditionally established remedy to alter
Disease Causal Chain
Dr. Raghunath A Mashelkar
Who suffers?
Patients are deprived of
Several nutraceuticals and functional foods or
Lifestyle modalities capable of
Preventing or reversing the viral disease
Dr. V Prakash
Side effects
Patients of viral diseases are subjected
to
Consuming drugs having
Tremendous side effects
Nutraceuticals and functional foods
Have lesser side effects
Disease Informatics
It is the application of Information
Science in
Defining the diseases with least error,
Identifying most of the targets to
Combat a cluster of diseases
(Disease Causal Chain) and
Designing a holistic solution
(Health strategy) to the problem
Depending the severity of the disease
Reference
Disease informatics for setting up Disease
definition, drawing Disease Causal Chain /
Web, marking Risk Events, Backend and
Frontend Events, and Health Problem
Solutions
http://bmj.bmjjournals.com/cgi/eletters/331/7516/566#134452
Thank you
This presentation is dedicated to
Dr. Ulhas V Wagh