i have a question:
estimate the prevalence of diabetes mellitus for a screened workforce
of 10000 employees among whom 1000 workers are detected with diabetes
mellitus during the initial screening and 45 new diagnosis are
detected at a subsequent annual screen 1 year later.
i think the answer, will be 0.1045
now for the same question if we want to calculate the incidence rate
(per person-years) what will be the answer??
> i have a question:
> estimate the prevalence of diabetes mellitus for a screened workforce
> of 10000 employees among whom 1000 workers are detected with diabetes
> mellitus during the initial screening and 45 new diagnosis are
> detected at a subsequent annual screen 1 year later.
> i think the answer, will be 0.1045
> now for the same question if we want to calculate the incidence rate
> (per person-years) what will be the answer??
I believe that would be 45/10,000 or 4.5/1000 since incidence includes only
new cases. The ones you detected at the beginning of the year were not new
in that they were already suffering from the disease.
Usman
On Sat, Sep 5, 2009 at 9:32 PM, md.wael <md.w...@gmail.com> wrote:
> i have a question:
> estimate the prevalence of diabetes mellitus for a screened workforce
> of 10000 employees among whom 1000 workers are detected with diabetes
> mellitus during the initial screening and 45 new diagnosis are
> detected at a subsequent annual screen 1 year later.
> i think the answer, will be 0.1045
> now for the same question if we want to calculate the incidence rate
> (per person-years) what will be the answer??
> i have a question:
> estimate the prevalence of diabetes mellitus for a screened workforce
> of 10000 employees among whom 1000 workers are detected with diabetes
> mellitus during the initial screening and 45 new diagnosis are
> detected at a subsequent annual screen 1 year later.
> i think the answer, will be 0.1045
> now for the same question if we want to calculate the incidence rate
> (per person-years) what will be the answer??
> I believe that would be 45/10,000 or 4.5/1000 since incidence includes only
> new cases. The ones you detected at the beginning of the year were not new
> in that they were already suffering from the disease.
> Usman
> On Sat, Sep 5, 2009 at 9:32 PM, md.wael <md.w...@gmail.com> wrote:
> > i have a question:
> > estimate the prevalence of diabetes mellitus for a screened workforce
> > of 10000 employees among whom 1000 workers are detected with diabetes
> > mellitus during the initial screening and 45 new diagnosis are
> > detected at a subsequent annual screen 1 year later.
> > i think the answer, will be 0.1045
> > now for the same question if we want to calculate the incidence rate
> > (per person-years) what will be the answer??
hi,
when not stated you assume the new cases occured at mid yea . in this
instance the new cases will contribute 45*0.5=22.5 person years free
from disease
The total person-years(denominator) will be 9000-22.5=8977.5
the incidence will therefore be 45/8977.5 person years
On Sep 5, 6:32 pm, "md.wael" <md.w...@gmail.com> wrote:
> i have a question:
> estimate the prevalence of diabetes mellitus for a screened workforce
> of 10000 employees among whom 1000 workers are detected with diabetes
> mellitus during the initial screening and 45 new diagnosis are
> detected at a subsequent annual screen 1 year later.
> i think the answer, will be 0.1045
> now for the same question if we want to calculate the incidence rate
> (per person-years) what will be the answer??
I think in this case we dont need to have calculate the person years as it
is the prevalence not incidence. Here we take total cases out of total
population at the beginning of the study. Unless, untill specified we cant
take person years into consideration. so answer 0.1045 is correct.
On Sat, Sep 19, 2009 at 10:29 PM, eric <oso...@gmail.com> wrote:
> hi,
> when not stated you assume the new cases occured at mid yea . in this
> instance the new cases will contribute 45*0.5=22.5 person years free
> from disease
> The total person-years(denominator) will be 9000-22.5=8977.5
> the incidence will therefore be 45/8977.5 person years
> On Sep 5, 6:32 pm, "md.wael" <md.w...@gmail.com> wrote:
> > i have a question:
> > estimate the prevalence of diabetes mellitus for a screened workforce
> > of 10000 employees among whom 1000 workers are detected with diabetes
> > mellitus during the initial screening and 45 new diagnosis are
> > detected at a subsequent annual screen 1 year later.
> > i think the answer, will be 0.1045
> > now for the same question if we want to calculate the incidence rate
> > (per person-years) what will be the answer??
-- Dr Vishal Dogra MPH
Programme Coordinator (Capacity Building)
International Clinical Epidemiology Network (INCLEN)
F 1/5, 2nd Floor, Phase I,
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Phone: +911147730040 (O) +91-99992-63613(M)
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