Which of the following statements is not true about incidence?
Incidence decreases when a programme is effective
Vaccination strategies decrease the incidence of a disease
Newer and effective treatment modalities decrease the incidence
Incidence implies number of new cases detected over a fixed time
Ans: C. Newer and effective treatment modalities decrease the incidenceRef: Park 24Ic p67, 23Ie p62, 22/c p59).Newer and effective treatment modalities do not decrease the incidence.Improvements in treatment may decrease the duration of illness and may decrease prevalence.Relation between Incidence & PrevalenceGiven the assumption that population is stable & incidence and duration are not changing.Prevalence = Incidence x Mean duration of diseasePrevalence describes balance between incidence, moality & recoverye.Incidence reflects causal factorse.Duration reflects prognostic factorse