calculations Flashcards
(22 cards)
Positive predictive value Ppv
True positives/total positives
Negative predictive value Npv
True negatives /total negatives
postnatal timeframe
1st week
post neonatal timeframe
28 days - 1 year
Fetal loss
sum of fetal deaths plus abortions
fetal death rate
fetal death cases/infants born that year x 100
General fertility rate
live births / mid year female population between ages 15 and 49
total fertility rate
number of children avg woman bears from ages 15-49,
conforming to the age specific fertility rates
TFR above 2, growing population
TFR below 2, pop decreasin
Gross reproduction rate
GRR = TFR x fraction of female births. 0.488 if not given
Net reproduction rate
GRR but accounting for mortality
if NRR = each child bearing women is replaced by a daughter.
Net reproduction rate
GRR but accounting for mortality
if NRR = each child bearing women is replaced by a daughter.
Maternal mortality
deaths during pregnancy thru 42 days post-natal/ births in that year
x 100,000
Population growth
= Crude birth rate = Crude death rate
positive = natural increase negative = natural decrease
Population growth
= Crude birth rate = Crude death rate
positive = natural increase negative = natural decrease
Relative risk
abs risk in exposed / abs risk in unexposed
Attributable risk
Risk Exposed - Risk unexposed
Cumulative incidence
Events/number of people
Incidence rate or incidence density
Events/(number of people x time)
Odds ratios for:
weak
moderate
strong associations
- 2 - 1.5
- 5 - 3.0
3 - 10
Odds ratio
odds of exposure among cases /
odds of exposure among controls
Calculate odds from prevalence
prevalence/(1-prevalence)
Types of prevention, primary secondary tertiary quaternary
Primary prevention strategies intend to avoid the
development of a disease
• Secondary prevention strategies attempt to diagnose
and treat an existing disease in its early stages before it results in significant morbidity
• The aim of terrtiary prevention is to reduce the
negative impact of established disease by restoring
function and reducing disease-related complications
• Quaternary prevention describes the set of health
activities avoid the consequences of excessive interventions in the health system
