Pulse blood pressure and cardiovascular mortality in a population-based cohort of elderly Costa Ricans.

UNLABELLED: We studied the relationships between blood pressure (BP), pulse pressure (PP) and cardiovascular (CV) death in older adults using data from 2346 participants enrolled in the Costa Rican CRELES study, mean age 76 years (s.d. 10.2), 31% qualified as wide PP. All covariates included and analyzed were collected prospectively as part of a 4-year home-based follow-up; mortality was tracked for an additional 3 years, identifying 266 CV deaths. Longitudinal data revealed little change over time in systolic BP (SBP), a decline in diastolic BP, and widening of PP. Wide PP was associated with higher risk of CV death but only among individuals receiving antihypertensive drug therapy. Individuals with both wide PP and receiving therapy had 2.6 hazard rate of CV death relative to people with normal-PP plus not taking treatment (TRT), even adjusting for SBP. Increasing PP between visits was significantly associated to higher CV death independently of TRT status. SBP and DBP were not significantly associated to CV death when the effect of PP was controlled for. CONCLUSION: elderly hypertensive patients with wide or increasing PP, especially if receiving TRT, are the highest CV risk group, thus must be carefully assessed, monitored and treated with caution.

Infectious disease transmission and infection-dependent matching.

This paper uses commonly available prevalence estimates to bound future incidence. The bounds rely on restricting the fraction of contacts between individuals of different infection statuses. It is argued that these bounds can be further tightened by restrictions of economic models of infectious disease that imply that uninfected individuals have larger incentives to avoid matching with infected individuals than do the infected individuals themselves. This implies that incidence predictions from canonical models of infectious disease are worst-case upper bounds, with the degree to which they overestimate new cases being monotonically related to this type of infection-dependent matching. Evidence in support of the economic type of infection-dependent matching is presented, by using data on the joint distribution of partners' HIV statuses in a random sample of couples from San Francisco in 1988-1989.

An empirical examination of the implications of assortative matching on the incidence of HIV.

Using data from The San Francisco Home Health Study (SFHHS), this paper analyzes the degree to which the incentives to avoid HIV infection result in infection-dependent (assortative) matching patterns based on HIV status. The incidence implications induced by such matching are compared to infection independent matching, an implicit assumption in canonical models within epidemiology. We estimate that an HIV-positive individual is more than twice as likely as an HIV-negative individual to have an HIV-positive partner, and that this results in a decrease in HIV incidence of about one-third compared to the predictions implied by standard epidemiological models.