Clinical Briefs

By Louis Kuritzky, MD

Influenza Vaccination and Reduction in Hospitalizations

Despite the fact that influenza and its consequences are well recognized, the number of at-risk individuals for serious sequelae to an influenza infection who receive vaccination remains suboptimal. Perhaps some clinicians remain unconvinced of the efficacy of influenza vaccine to reduce important outcomes. Nichol and colleagues studied the effect of influenza vaccine in 2 successive years (1998-2000) upon a large cohort (n = 140,000) of senior citizens aged 65 or older, which represent pooled data from 3 large managed-care organizations.

In each of these 2 influenza seasons, just over half of the population were immunized (55.5, 59.7%, respectively). Outcomes measured included odds of hospitalization for cerebrovascular disease, cardiac disease, and pneumonia or influenza. All-cause mortality was also assessed.

Influenza vaccination was associated with reductions in all outcomes measures, including 16-23% for cerebrovascular disease, 19% for cardiac disease, and 29-32% for pneumonia or influenza. Influenza vaccination was associated with a 48-50% reduction in all-cause mortality.

Only about two-thirds of senior citizens in the United States received influenza vaccination in 2001, leaving a very substantial gap from the intended current goal of 90% immunization. Perhaps such robust associations of influenza vaccine with favorable outcomes will stimulate clinicians to re-invigorate their energies toward enhanced vaccination.

Nichol KL, et al. N Engl J Med. 2003;348:1322-1332.

Screening Men for Prostate and Colorectal Cancer

Prostate cancer (P-CA) and colorectal cancer (C-CA) do not share the same evidence base for potential efficacy in reducing mortality. For P-CA, there remain no data to confirm whether screening with PSA will lead to reductions in all-cause mortality. Even the recent trials, which have confirmed reductions in P-CA related mortality from cancers discovered by PSA screening, have not shown a reduction in all-cause mortality, leading to great uncertainty about the overall benefits for an individual patient and divergence of opinion by major policy making bodies about the best course of action for PSA screening. C-CA, on the other hand, is endorsed by essentially all policy-making and consensus groups, based upon multiple randomized controlled trials that show reductions in C-CA mortality with FOBT, and probably even greater benefit with sigmoidoscopy or colonoscopy.

The Behavioral Risk Factor Surveillance system is an annual study that obtains information for the CDC by random-digit dialing telephone surveys. In these data, questions about P-CA and C-CA screening in men older than 40 were included in 2001 (n = 49,315).

In this large population, 75% of men older than age 50 had undergone PSA testing, and the likelihood increased with increasing age. In contrast, only 63% of men in the same age group had been screened with either FOBT or endoscopy. Considering that an approximately equal number of deaths occur from these 2 disorders (C-CA = 27,800; P-CA = 30,200 estimated for the year 2002), and the considerably less robust evidence for the efficacy of P-CA screening, clinicians would be wise to expend more intensive energies to enhance C-CA screening practices.

Sirovich BE, et al. JAMA. 2003;289: 1414-1420.

Weight Loss in CHF and Treatment with ACE-I

Weight loss to the degree of cachexia complicates cancer, some infectious diseases (eg, HIV, thyrotoxicosis), and less obviously, perhaps, heart failure (CHF). It has been previously noted in a small, prospective study of CHF patients that substantial weight loss (SWL) is associated with adverse effect upon survival, independent of other risk factors.

By analyzing the data from patients in a large treatment trial of CHF using ACE inhibitors (the SOLVD trial, n = 2569), Anker and colleagues investigated weight changes, the relationship of weight change to mortality, and the effect of ACE inhibitor treatment upon weight loss in a subgroup of the SOLVD trial (n = 1929).

In this data set, weight loss was independently related to reduced survival, independent of age, sex, New York Heart Association Class, ejection fraction, and even treatment allocation. In crude adjusted analysis, a weight loss of 6% or greater was the strongest predictor of reduced survival.

Anker et al comment that weight loss in CHF is not abrupt, but rather gradual, and represents diverse tissue compartment losses, including muscle, fat, bone, and the heart itself. They suggest that a 6% or greater weight loss be considered definitional for cardiac cachexia.

Anker S, et al. Lancet. 2003;361: 1077-1083.

Dr. Kuritzky is Clinical Assistant Professor, University of Florida, Gainesville.