Isoniazid for preventing tuberculosis in non-HIV infected persons.

BACKGROUND: Although isoniazid (INH) is commonly used for treating tuberculosis (TB), it is also effective as preventive therapy. OBJECTIVES: The objective of this review was to estimate the effect of 6 and 12 month courses of INH for preventing TB in HIV-negative people at increased risk of developing active TB. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline, Embase and reference lists of articles. We hand-searched Science Citation Index and Index Medicus. SELECTION CRITERIA: Randomised trials of INH preventive therapy for 6 months or more compared with placebo. Follow-up for a minimum of 2 years. Trials enrolling patients with current or previously treated active TB, or with known HIV infection, were excluded. Criteria were applied by two reviewers independently. DATA COLLECTION AND ANALYSIS: Trial quality was assessed by two reviewers independently, and data extracted by one reviewer using a standardized extraction form. MAIN RESULTS: Eleven trials involving 73,375 patients were included. Trials were generally of high quality. Treatment with INH resulted in a relative risk (RR) of developing active TB of 0.40, (95% confidence interval ¿CI¿ 0.31 to 0.52), over two years or longer. There was no significant difference between 6 and 12 month courses (RR of 0.44, 95% CI 0.27 to 0.73 for six months, and 0.38, 95% CI 0.28 to 0.50 for 12 months). Preventive therapy reduced deaths from TB, but this effect was not seen for all cause mortality. INH was associated with hepatotoxicity in 0.36% of people on 6 months treatment and in 0.52% of people treated for 12 months. REVIEWER'S CONCLUSIONS: Isoniazid is effective for the prevention of active TB in diverse at-risk patients, and six and 12 month regimens have a similar effect.

Recognizing and investigating iron-deficiency anemia in hospitalized elderly people.

OBJECTIVE: To determine whether anemia is documented and appropriately investigated for iron deficiency in hospitalized elderly people. DESIGN: Retrospective chart review. SETTING: Medical clinical teaching unit (CTU) in secondary care hospital in Hamilton, Ont. PARTICIPANTS: Consecutive patients 65 years of age or older admitted between April 1992 and March 1993. OUTCOME MEASURES: Proportion of anemic patients for whom documentation was adequate (included in problem list in patient chart) and for whom adequate investigations were performed (measurement of serum ferritin level in anemic patients in whom iron deficiency was suspected, bone-marrow aspiration for those with intermediate probability of iron deficiency after determination of serum ferritin level, and endoscopy of upper or lower gastrointestinal tract, or both, in patients with iron deficiency). RESULTS: Of 183 eligible patients admitted to the CTU 66 (36%) had anemia, in 47 cases (71%) the anemia was documented by house staff or attending physicians. Of the 66 anemic patients 49 had a non-macrocytic anemia of unknown cause: 26 had their serum ferritin level measured, 5 underwent bone-marrow aspiration, and 21 were referred for gastrointestinal endoscopy. Six of eight patients with probable iron deficiency (i.e., a serum ferritin level that was diagnostic [less than 18 micrograms/L] or suggestive [18 to 45 micrograms/L]) underwent endoscopy, two were found to have cancer of the stomach or cecum. Only 26 of the 49 patients had adequate investigation. CONCLUSIONS: Anemia is common among elderly patients in hospital. However, iron deficiency is underrecognized and underinvestigated.