MAIN EPIDEMIOLOGICAL CHARACTERISTICS IN SHOE-LEATHER EPIDEMIOLOGY
CONDUCTED BY JOHN SNOW IN 1854.
The key characteristics in Shoe-Leather Epidemiology by John Snow
conducted in 1854 consists of the following:
Focus: The Shoe-Leather Epidemiology
conducted by John Snow focused on the population that died due to Cholera due
to the source of water supply in London during 1849 – 1854.
Furthermore, John Snow focused his study on the population which was supplied water by Southwark & Vauxhall
Company which drew water from the polluted part of Thames River. Next, Lambeth
Company which relocated its water intake to less contaminated part of the
Thames. (Table: 1-5 Snow. J: modes of communication of Cholera).
The distribution pattern of Shoe Leather Epidemiology of John Snow
was on the number of deaths that occurred in London during 1849 – 1854 due to
The determinants which were studied included firstly those homes
which received water from Southwark & Vauxhall Company; secondly the homes
receiving water by Lambeth Company.
The outcome of the natural experiment conducted by John Snow
concluded high deaths were the consequent result of contaminated water which
was associated with Cholera.
In his natural experiment John Snow focused on finding the
association between the deaths that were caused due to Cholera in London during
1849 – 1854 and the source of drinking water to these homes of London.
Epidemic: John Snow studied the occurrence of deaths due to Cholera in
association with the source of water supply in one district of London, plotting
it against similar deaths in another district.
Distribution: John Snow
listed the water supply company wise against the number of houses, deaths from
Cholera and deaths per 10,000 houses.
HIGHER RISK OF CARDIOVASCULAR
to World Health Organization (WHO), the Cardiovascular Disease are the group of
disorders of heart and blood vessels that may lead to Hypertension, Coronary
Heart Disease, Stroke, Heart failure to name a few.
Risk Factors: The
Risk Factors in this study would be as follows:
o Age: According to the study conducted by Moazaffarian.D et.al (2015)
and published by American Heart Association, Americans aged 60 years &
above stand at a very higher level of prevalence of Cardiovascular Disease.
o Sex: According to the study conducted by Moazaffarian.D et.al (2015) and
published by American Heart Association (AHA), Men above the age of 60 years
stand at a significantly higher
prevalence rate when compared to Women of the same age.
o High Blood Pressure: American Heart Association (AHA) reported as per the studies
conducted, the people with higher blood pressure (b.p) stands at higher risk
than people with normal blood pressures.
Also, people with high blood pressure
along with Diabetes Mellitus Type – II have twice higher chances of developing
o Diabetes: Especially Diabetes Mellitus Type – II is a known risk factor for
Cardiovascular Disease. Diabetes Mellitus Type – II along with co-risk factor
& comorbidity significantly increases the risk of Cardiovascular Disease.
o Abnormal Cholesterol &
Triglycerides: American Heart
Association (AHA) reported patients with high LDL Cholesterol (bad
cholesterol), low HDL Cholesterol (good cholesterol) and high triglycerides are
at significant risk to develop Cardiovascular Disease.
o Obesity: As per the Centre for Disease Control & Prevention (CDC) obesity
is a major risk factor for Cardiovascular Disease & it has been strongly
associated with Diabetes Mellitus Type – II.
o Excessive Alcohol & Smoking: For each respectively American Heart Association (AHA) & Centre
for Disease Control & Prevention (CDC) has put individuals who consume
excessive alcohol & smokes at higher risk for Cardiovascular Disease
irrespective of their Diabetes status.
Exposures: The Exposure of the subjects in the study will be mapped by
studying the exposed groups which would be as follows:
o Age: As per the report of WHO published in the year 2015, higher the
age; higher are the prevalence rates of Cardiovascular Disease.
o Sex: As per the study conducted by Moazaffarian.D et.al (2015) &
published by American Heart Association (AHA), the prevalence rate of Men in
the age group of 60-79 years is higher than Females in same age group. Whereas
in the age group of 80+, Females were at higher risk to develop Cardiovascular
o Diabetes: As per the data published by WHO, AHA, CDC; diabetic population along
with cofactor & comorbidity is higher prevalent for Cardiovascular Disease.
o Obesity: WHO reports people with higher body weight, less physical activity
are a major exposed group to Cardiovascular Disease.
Outcome: The outcome of this study have to be clearly defined to map
how common Cardiovascular Diseases are in
the population as per measurement of morbidity & mortality trends.
The measurement aspect shall be defined for
specific signs, symptoms & emphasis on diagnostic tests for respective
to Developing a Protocol for observational & Effective Research: User Guide
by Velentgs.P et.al (2013) the outcomes of epidemiological study are to be
divided as follows;
o Clinical Outcomes Are very
important outcomes to be considered as per medical treatments provided to
subjective patients which are to be mapped effectively. Apart from the blood tests, few other diagnostic tests which are
done include X-Ray, ECG, Cardiac Catheterization, Cardiac CT, Cardiac MRI, etc.
o Patient Reported Outcomes: These are the outcomes which are based on the patient’s own
perspective ex: uneasiness, giddiness, pain elevation.
MY MAJOR AT WKU:
My Major at WKU is Healthcare Administration. In my view, the role
of the Hospital Administrator have elaborated in the current healthcare
scenario as Administrators are responsible to present an environment to
clinicians in which there is prominent, qualified & competent staff,
correct systems & workable models are in place, smooth functional machinery
installed, adequate supply of medicines & related consumables with proper
infrastructure which is taken care round the clock. Most importantly
interacting with patients, doctors, nurses & other allied staff catering to
the community, finding the answers for the betterment of community has made me
choose Healthcare Administration as my major.
With rapid changes in healthcare delivery systems specialized
understanding of Epidemiology is a necessary for Hospital Administrators who
shall focus on delivering care to populations than the specific patient need
care P.J Et.al Healthcare Adm. Edu (1998).
EPIDEMIOLOGY IN MY AREA:
textbook definition of Epidemiology is “the science/study
of the distribution & determinants of disease in a human population.”
per the definition Epidemiology is;
Study: it is the
study of the health of the population.
Distribution: who, when, where it occurs.
Determinants: searching for the causes.
Populations: geographically defined population.
cases of illness.
Control: health promotion/prevention
Morris JN. “Uses of Epidemiology” 3rd
Ed. Edinburg, the UK lists the uses
of Epidemiology as follows;
study history of health population
diagnose health community
study working of health services
estimate individual risks of disease
compute clinical picture
search for causes
Health System Delivery published 2007 gives the Epidemiology Model for Health
System which is as;
The incidence of Hypertension in Patients with Diabetes Mellitus –
Epidemiological Study in My Area:
As per the data of WHO, during the year 2000, South-East Asia had 46 Million Diabetic
population of which India accounted for 31 Million diabetics, it is expected
that Indian Diabetic Population will reach 79 Million by the year 2030.
WHO data of
2008 shows 32.5% of the Indian population is Hypertensive. Hypertension is a
known cause of Cardiovascular Diseases, stroke, ischemic
heart disease. Hypertension with comorbidity of Diabetes doubles the rate of these
diseases El. Ataf et.al 2004.
Association data of 2015 says the Indian city of Hyderabad, Telangana was the
then diabetic capital of the world.
Epidemiological study to find the incidence of Hypertension in diabetic
patients is rightly needed.
Key Characteristics of the Study:
The objective of
study: To find the incidence of
hypertension in the diabetic population.
The distribution of the study is as follows;
o Who: Diabetic Patients who visit ABC Hospital – Hyderabad,
Telangana – India, aged between 18 – 80 years, both males & females &
those patients who do not suffer from any other chronic disease.
o Where: Patients
visiting ABC Hospital – Hyderabad, Telangana – India.
o When: During 01-01-2014 & 31-12-2017 are included in the study.
To monitor subjects (patients) included in the study especially for;
sugar test results
can be divided into two groups – one diabetic patient
Without Hypertension & in another Diabetic
patient With Hypertension.
Each month as
the patients (subjects) visits the ABC Hospital for their monthly examination, he/she is to be mapped for all above criteria
& deviation if any found shall be noted accordingly.
All patients who visit ABC Hospital – Hyderabad, India during the
study period aged between 18 – 80 years either male/female
& who are free from other chronic diseases.
Definition: Patients with
Diabetes Mellitus Type-II who show deviations from normal systolic &
diastolic blood pressures are to be added to
a subject group named Diabetes & who
Proportion (Cumulative Incidence) considering the deaths/loss follow-up is calculated as;
I = No.
of new cases of DM Type-II & HTN during the study period
of persons at risk of developing – 0.5 * No. of deaths/loss follow-up
beginning of the study
Person-time will be
calculated as = total follow-up * time contributed by each person
Rate (IR) is calculated as;
No. of New cases