Transcript Basic Epidemiologic Concepts

Community Medicine V
Dr. Mehrdad Askarian MD, MPH
Professor of Community Medicine
Peptic ulcer
&
IBD
Peptic ulcer epidemiology
• Trend
– Increase till 1960, then decrease
hospitalization around 1970.
• Points regarding epidemiology of PU:
– Method of case finding
» History, admission, Operation, death, radiography,
endoscopy
– Season of assessment
– DDx with esophagitis, dyspepsia
– Management facilities
– ICD 9-10 etc.
Peptic ulcer epidemiology
• Age and Sex:
– Duodenal ulcer happens 20 years earlier than
gastric ones, prevalence in young males is
decreasing, but increasing in old age,
females.
– Increase age increases risk of infection with
H. Pylori
– Increase prescription of NSAIDs especially in
old people.
– Cigarette smoking especially among young
females.
Peptic ulcer epidemiology
• Geographic distribution, race, social factor
– There are differences, but not known the
etiology.
– Not predictable.
Peptic ulcer epidemiology
• Cigarette smoking
– Risk factor for incidence of disease,
prevalence, recurrence, complications.
• Increase risk when smoke more.
• Decreases wound recovery and increase
recurrence.
• Increase complications, need for operation
& post op. complications.
• Increase mortality rate due to
cardiopulmonary and/or wound
complications.
Peptic ulcer epidemiology
• Diet
– Decrease in fatty acids which causes
decrease in mucosal prostaglandins in
mucosa that predisposes to duodenal ulcer??
– Rice or wheat??
– Inappropriate food preservation due to
microbial contamination.
– Coffee??
Peptic ulcer epidemiology
• Gene
– O blood group increase risk of duodenal ulcer
– 20-50% of those who have peptic ulcer have
+ve family history of the same disease vs. 515% in those who do not have this history.
Peptic ulcer epidemiology
• H. Pylori
• About 50% of world population are infected and
is equal in both sex. (Australia: 21%, China:
66%, India: 79%), (Iran: 7-18 y/o: 40.9%, 3%
increment yearly in this group, >45 y/o is 75.6%
which shows 1% increment yearly in this group),
better socioeconomic status decrease
contamination prevalence.
• Infection rate differs by age and area of living
Peptic ulcer epidemiology
• H. Pylori
– Environmental factors
• Mostly in young age, crowded areas, families,
common vehicles, lack of personal and/or social
hygiene.
– Genetic factors
• Identical twins have more co-infection than other
age group matched.
– Level of education
• The higher the education, lower the rate of
infection
Inflammatory bowel disease
• Ulcerative colitis
• Crohn disease
Ulcerative colitis
• Epidemiology
– Young adult (20-40 y/o) (Iran: 20-50 y/o)
– Female>male
– White> Black
– Socioeconomic class has positive relation
Ulcerative colitis
• Risk factors
– Genetic factors
• More prominent in crohn disease
• 10-20% in father, mother or siblings.
– Environmental factors
• Infectious agents
– E.coli
• Food hypersensitivity
– ± milk
• Cigarette smoking
– Is more common in non smokers (in contrast with crohn)
• OCP
– Weak correlation
• Appendectomy
– Has been shown that patients with UC has less history of
appendectomy.
Crohn disease
• Increasing the rate of crohn, when uc has
decreased or been stable.
• More common in young age groups, peak
in 80 y/o
• Male=female
• Genetic factors are involved
• Environmental factors
– Cigarette smoking increases the risk
Any
Comments or
Questions?