NR 503 Study Guide for Final Exam

NR 503 Study Guide for Final Exam
I I I I I I




1. Objectives Iof Iepidemiology
a. Understand Ithe Iaetiology Ior Icause Iof Ia Idisease I(risk Ifactors)
b. Find Iout Ithe Iextent Ithat Ia Idisease Ior Ihealth Iproblem Iaffects Ia Icommunity Ior
Ipopulation

c. Determine Ithe Inatural Ihistory Ior Iprognosis
d. Evaluate Iexisting Iand Inewly Ideveloped Ipreventative Itherapeutic Imeasures Iand
Imodes Iof Ihealthcare Idelivery

2. Define, Icompare, Icalculate, Iand Iinterpret IMeasures Iof IMorbidity
a. Incidence Irate: Imeasurement Iof Ithe Inumber Iof Inew Iindividuals Iwho Icontract Ia
Idisease Iduring Ia Iparticular Iperiod Iof Itime

i. Calculation: INumber Iof Inew Icases Iof Idisease Ior Iinjury Iduring Ispecified
Iperiod IDIVIDED IBY ISize Iof Ipopulation Iat Istart Iof Iperiod

b. Attack Irate: ISame Ias Irisk, Iproportion Iof Iindividuals Iin Ia Ipopulation I(initially IfreeIof
Idisease) Iwho Idevelop Ithe Idisease Iwithin Ia Ispecified Itime Iinterval.

i. Calculation: ITotal Inumber Iof Inew Icases IDIVIDED IBY IThe Itotal Ipopulation
c. Prevalence: Imeasurement Iof Iall Iindividuals Iaffected Iby Ithe Idisease Iat Ia Iparticular
Itime

i. Calculation: INumber Iof Inew Icases Iof Idisease Ior Iinjury Iduring Ispecified
Iperiod IDIVIDED IBY ITime Ieach Iperson Iwas Iobserved, Itotaled Ifor Iall

Ipersons

d. These Irates Iare Iused Ito Imeasure Idisease Ioccurrence Iand Imake Icomparisons
Ibetween Ipopulation Igroups. IThey Iare Icommonly Iused Imeasures Ithat Ihelp Iour

Iunderstanding Iof Ithe Idistribution Iof Idisease Iin Ia Igiven Ipopulation.

3. Understand Iwhy Iincidence Idata Iare Iimportant Ifor Imeasuring Irisk.
a. Incidence Iis Iimportant Ifor Imeasuring Irisk Ibecause Iit Itells Iyou Ithe Irate Iat Iwhich
Inew Ipeople Iare Icontracting Ithe Idisease

4. Define, Icompare, Icalculate, Iand Iinterpret IMeasures Iof IMortality
a. Mortality: Ia Imeasure Iof Ithe Ifrequency Iof Ioccurrence Iof Ideath Iin Ia Idefined
Ipopulation Iduring Ia Ispecified Iinterval. IMorbidity Iand Imortality Imeasures Iare

Ioften Ithe Isame Imathematically; Iit's Ijust Ia Imatter Iof Iwhat Iyou Ichoose Ito Imeasure,

Iillness Ior Ideath.

i. Calculation: IDeaths Ioccurring Iduring Ia Igiven Itime Iperiod IDIVIDED IBY ISize
Iof Ithe Ipopulation Iamong Iwhich Ithe Ideaths Ioccurred I TIMES I10
n

b. Cause-specific Imortality Irate: IThe Imortality Irate Ifrom Ia Ispecified Icause Ifor Ia
Ipopulation.

i. Calculation: IThe Inumber Iof Ideaths Iattributed Ito Ia Ispecific Icause IDIVIDED
IBY IThe Isize Iof Ithe Ipopulation Iat Ithe Imidpoint Iof Ithe Itime Iperiod

c. Annual Imortality Irate: I The Irate Iof Ideath Iin Ia Ione-year Iperiod.
i. Calculation: IDeaths Ioccurring Iwithin Ithe Ione-year Iperiod IDIVIDED IBY ISize
Iof Ipopulation Iin Iwhich Ithe Ideaths Ioccured

, d. Case-fatality: Ithe Iproportion Iof Ideaths Iwithin Ia Idesignated Ipopulation Iof I"cases"
I(people Iwith Ia Imedical Icondition) Iover Ithe Icourse Iof Ithe Idisease

i. Calculation: Ihe Inumber Iof Ideaths Ifrom Ia Ispecified Idisease Iover Ia Idefined
Iperiod Iof Itime IDIVIDED IBY IThe Inumber Iof Iindividuals Idiagnosed Iwith Ithe

Idisease Iduring Ithat Itime ITIMES I100 I(final Ianswer Ishould Ibe Ipercentage)

e. Proportionate Imortality: Ithe Iproportion Iof Ideaths Iin Ia Iparticular Ipopulation IoverIa
Ispecified Iperiod Iof Itime, Iattributable Ito Idifferent Icauses

i. Calculation: INumber Iof Ideaths Iwithin Ia Ipopulation Idue Ito Ia Ispecific
Idisease Ior Icause IDIVIDED IBY Ithe Itotal Inumber Iof Ideaths Iin Ithe Ipopulation

Iduring Ia Itime Iperiod Isuch Ias Ia Iyear.

5. Assess Ithe IValidity Iand IReliability Iof IDiagnostic Iand IScreening ITests
a. Define, Icompare Iand Icalculate Imeasures Iof Ivalidity, Iincluding Isensitivity Iand
Ispecificity.

i. Sensitivity Iidentifies Ithe Iproportion Iof Iindividuals Iwho Itruly IDO Ihave Ithe
Idisease IAND Iare Igiven Ia Ipositive Itest Iresult. II Ifind Iit Ihelpful Ito Iremember:

IsensiTivity I= Isensitive Ito Ithe ITruth I(i.e. Ido Ihave Idisease I+ Ido Ihave Ipositive

Iresult)

1. We Iwant Ito Iknow Iwhat Iproportion Iof Iindividuals Iwho Ihave Ithe
Idisease I(a+c) Iwere Igiven Ia Ipositive Itest Iresult I(a), Itherefore…

a. Sensitivity I= Ia/(a+c)
ii. Specificity Iidentifies Ithe Iproportion Iof Iindividuals Iwho Itruly IDO INOT Ihave
Ithe Idisease IAND Iwere Igiven Ithe Icorrect Inegative Itest Iresult. II Ifind Iit

Ihelpful Ito Iremember: Ispecificity I= IspeciFies Ithe IFalse I(i.e. Ido Inot Ihave

Idisease Iand Ido Inot Ihave Ipositive Itest Iresult

1. This Itime Iwe Iwant Ito Iknow Iwhat Iproportion Iof Ipeople Iwho Ido Inot
Ihave Ithe Idisease I(b+d) Iwere Igiven Ithe Icorrect Inegative Itest Iresult

I(d), Itherefore…

a. Specificity I= Id/(b+d).
b. Define Iand Icalculate Ipositive Ipredictive Ivalue.
i. Positive IPredictive IValue: IThe Iprobability Ithat Isubjects Iwith Ia Ipositive
Iscreening Itest Itruly Ihave Ithe Idisease.

1. Calculation: Ia/(a+c)
c. Understand Ipositive Ipredictive Ivalue I(PPV) Iand Irelationship Ito Idisease
Iprevalence Iand Ispecificity Iof Ia Iscreening Itest.

i. Higher Iprevalence/specificity Irates=higher IppvIrates
6. Epidemiologic Itransition
a. Phase Iof Idevelopment Iwitnessed Iby Ia Isudden Iand Istark Iincrease Iin Ipopulation
Igrowth Irates Ibrought Iby Iimproved Ifood Isecurity Iand Iinnovations Iin Ipublic Ihealth

Iand Imedicine, Ifollowed Iby Ia Ire-leveling Iof Ipopulation Igrowth Idue Ito Isubsequent

Ideclines Iin Ifertility Irates.

7. Study Idesigns I(case-control, Icross Isectional, Iprospective Iand Iretrospective Icohort, Iclinical
Itrial)

a. Case-control Istudy: IAn Iobservational Istudy Ithat Icompares Ipatients Iwho Ihave Ia
Idisease Ior Ioutcome Iof Iinterest I(cases) Iwith Ipatients Iwho Ido Inot Ihave Ithe Idisease

Ior Ioutcome I(controls) Iand Ilooks Iback Iretrospectively Ito Icompare Ihow Ifrequently