title: A note on the grouping of surveillance data when adjusting for reporting delays.
abstract: Analyses that adjust disease incidence data for reporting delays are often based on grouped data. A way of grouping data based on the quarter in which a case is reported, using all cases reported by a given cutoff date, is compared with the usual method of categorization based on a time-delay between diagnosis and reporting. The two methods of tabulation are illustrated using cases of the acquired immunodeficiency syndrome (AIDS) diagnosed and reported in Australia. A simple simulation study confirms that estimates of adjusted quarterly AIDS counts based on the quarter of report grouping are less variable than those based on the time-delay grouping.
authors.affiliation: National Centre in HIV Epidemiology and Clinical Research, the University of New South Wales, Sydney, Australia.
authors.forename: M G
authors.initials: MG
authors.lastname: Law
authors.forename: J M
authors.initials: JM
authors.lastname: Kaldor
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000175:diagnosis / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D018563:Disease Notification / Q000379:methods* / Q000706:statistics & numerical data; D015497:HIV-1; D006801:Humans; D011159:Population Surveillance / Q000379:methods*; D012042:Registries / Q000706:statistics & numerical data; D013997:Time Factors