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.