Identifying the appropriate comparison group for HIV-infected individuals.
OBJECTIVE
HIV-infected individuals are living longer as a result of effective treatment. Age-related comorbidities now account for the majority of morbidity and mortality among treated HIV-infected adults. Previous findings regarding the age at, and risk of, these comorbidities have been mixed, sparking debate in the field. Discerning potential differences in the occurrence and burden of age-related comorbidities among treated HIV-infected adults as compared with uninfected adults of the same age requires careful selection of the appropriate uninfected comparison group.


RESULTS
The validity of comparisons with HIV-uninfected populations is threatened when differences in demographic, clinical, and lifestyle characteristics between HIV-infected and uninfected adults are not considered. Identifying a pool of HIV-uninfected individuals from existing secondary data resources and employing selection methodologies may be a novel approach to reduce threats to internal validity. Issues related to identifying data sources, understanding inclusion criteria, determining measurement error, and threats to inference are discussed.


CONCLUSIONS
The development of clinical interventions targeting age-related comorbidities will rely on deriving valid inferences from appropriate comparison groups. The use of secondary data resources and selection methodology to create the appropriate uninfected comparison group is an attractive approach in the setting of finite resources, but are not without limitations.
Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
Cherise
C
Wong
Keri
K
Althoff
Stephen J
SJ
Gange
D000375:Aging; D035843:Biomedical Research / Q000379:methods*; D015897:Comorbidity; D035061:Control Groups; D015658:HIV Infections / Q000150:complications* / Q000453:epidemiology*; D006801:Humans