In This Issue of Archives of Internal Medicine

Iatrogenic complications such as adverse drug events complicate the hospital stay of many older patients. In a prospective cohort study, Agostini and colleagues report that the commonly administered drug diphenhydramine resulted in a notably increased risk of cognitive decline. Delirium symptoms including inattention, disorganized speech, and altered consciousness occurred significantly more frequently in exposed older patients, in addition to increased risk of placement of a new urinary catheter and longer length of hospital stay. The risk of adverse events increased with the dose received. Notably, 24% of doses were inappropriately administered to older hospitalized patients. The widespread use of diphenhydramine should be reevaluated for the vulnerable older population.

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Over a 5-year period in an acute-care facility, 432 patients had pneumococcal bacteremia and more than 5% of these patients had recurrent bacteremic episodes. Coexistent cancer, human immunodeficiency virus infection, and female sex were all independent predictors of recurrent bacteremia. Only patients infected with human immunodeficiency virus had multiple recurrences. Patients with recurrent bacteremia had a higher mortality rate and were more likely to have penicillin-resistant pneumococcal infection, but neither of these findings was statistically significant. When a patient is found to have recurrent pneumococcal bacteremia, the presence of an underlying immunosuppressive condition should be investigated.

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Successful treatment of influenza depends on accurate diagnosis of illness and prompt intervention. However, there is a lack of data comparing clinical and laboratory diagnostic techniques. In this study, clinical diagnosis of community cases of influenza is compared with classical laboratory techniques used for diagnosis of influenza such as virus culture, paired hemagglutination inhibition serology, and newer molecular diagnostic methods (eg, multiplex reverse transcription polymerase chain reaction). A range of clinical symptoms were scored for severity, and correlation of symptom scores with laboratory diagnosis was evaluated. Total symptom scores at baseline showed a significant association toward greater severity with increasing number of positive test results (P<.001). Increasing number of positive test results also showed a significant correlation with a longer time to alleviation of symptoms of influenza (P = .001). The authors suggest that reverse transcription polymerase chain reaction be considered a gold standard for detection of influenza when presentation occurs within the first 48 hours of illness, concluding that when influenza was circulating and clinical diagnostic criteria were applied, diagnosis of influenza was accurate in more than 70% of adults on clinical grounds alone. This highlights the need for primary care physicians to be alerted to circulating influenza and to be aware that presentation with cough and fever are the most predictive symptoms.

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Clinical guidelines support a noninvasive "test-and-treat" strategy for Helicobacter pylori in individuals with uncomplicated dyspepsia. However, consensus is lacking regarding the preferred noninvasive testing method. A decision analytic model was used to estimate the clinical and economic outcomes associated with noninvasive tests designed to detect either H pylori antibody or active H pylori infection in patients subjected to the test-and-treat strategy. A simulated patient cohort with uncomplicated dyspepsia underwent antibody testing or testing to detect active H pylori infection (active testing). Individuals testing positive received eradication therapy. Outcomes assessed included appropriate and inappropriate treatment prescribed, cost per patient treated, incremental cost per unnecessary treatment avoided. Active testing led to a substantial reduction in unnecessary treatment for patients without active infection (antibody, 23.7; active, 1.4 per 100 patients) at an incremental cost of $37 per patient. The clinical advantage and cost-effectiveness of active testing was enhanced as the percentage of individuals with a positive antibody test from past, but not current, infection increased. In conclusion, active testing for H pylori infection significantly decreases the inappropriate use of antimicrobial therapy compared with antibody testing. The advantages of active testing should be enhanced as the widespread use of antimicrobial agents increases the proportion of patients with antibody to H pylori but without active infection.

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