(Solution) Assignment on Epidemiology

Running head: EPIDEMIOLOGY 1
Epidemiology
Name
Date of Submission

EPIDEMIOLOGY 2
Q1
The main aim of this study was to assess progressively whether recent exposure to
arsenic from drinking water and chronic infections were associated with all causes as well as
chronic disease deaths among the population in Bangladesh.
Q2. The criteria used for the selection of the study participants in this case was random
sampling upon meeting the inclusion and exclusion criteria. An advantage of this method is that
it gives and opportunity for any member of the population to be chosen as part of the sample. A
disadvantage of random sampling is that there are some features of the sample that are not part of
the study question and these might act as sources of bias.
Q3. The researchers were not able to get rid of loss of follow-up. This is because
although the research was structured in a way of active follow-up to the cohort. In this case, the
follow-up was structured in the phases throughout the study period. The first follow-up was
conducted between sept 2002 to May 2004, the second was in June 2004 to August 2006, and
thirst follow-up was from January 2007 to February 2009. In these follow-ups, there are some
months which have not been accounted for, and probably, there could be some losses of follow-
ups (Argos et al., 2010).
Q4. the results of this study indicated that there were 407 deaths between October 200 to
February 2009. The obtained multivariate adjusted hazard ratios for the all-cause mortalities as
compared to arsenic levels in 10.1-50, 50.1-150, and 150-864, with 10 least being in water
samples from well water was 1.34 at 95% CI, and 1.68 respectively. However, these findings
were similar to daily arsenic doses as well as the arsenic contained in urine. These findings
indicated that the chronic exposure to arsenic through drinking water was linked to increased
death rates among the population in Bangladesh. The data from this follow up study can be used

EPIDEMIOLOGY 3
to determine the long-term effects of exposure to arsenic from drinking water and the possible
effects of these exposure to the long-term effects. Additionally, the findings recommend the
adoption of relevant measures to counter the effects of human exposure to arsenic in drinking
water.
Q5. Advantage:
a. source of rich datasets for a research
b. It gives detailed information concerning the subject.
Disadvantage:
a. It is time consuming in terms of integrating different information to make a meaningful
conclusion.
b. It requires close keenness and thus might be subject to errors in making
ascertainments.
Q6. a. The primary exposure variables in this case were marital status, gender age and
arsenic. Gender was an important variable because there were variations of arsenic chronic
effects among men and women. Age was also relevant variable because the study participants
were required to be in the range of eighteen to seventy-five years. Marital status was an
important exposure because the households are the major source of contamination due to
consumption of contaminated drinking water.
b. The advantage of using marital status as a primary exposure variable is that it is
indicative that the family point is a possible point of exposure to arsenic in drinking water. It is at
the household levels that many people are likely to get exposed to arsenic levels in a short
duration of time. However, a disadvantage of this primary exposure variable is that being