HIV-related diarrhea: Measurement issues and the role of lactose intolerance.
Published: 2004
Language: eng
Number of pages: 195
Description: Introduction. This thesis had four principal objectives: (1) to identify and review the validation of existing measures of HIV-related diarrhea used in clinical trials; (2) to determine the effect of a moderate dose of lactose on the stool weight in HIV-related chronic non-infectious diarrhea (CNID); (3) to evaluate the usefulness and feasibility of further study of breath testing (BT) to diagnose lactase deficiency (LD) in this population; (4) to prospectively compare several measures of HIV-related diarrhea to provide preliminary data on their validity.Conclusions. Studies 1 and 4: Tools currently being used for the measurement of HIV-related diarrhea are varied but have reasonable face validity only. Preliminarily, stool frequency and stool form seem useful; further work is needed to determine a definitive measure of HIV-related diarrhea. Study 2: Lactose ingestion does not worsen HIV-related diarrhea, regardless of underlying LD. Ingestion of lactose-containing dairy products should not be discouraged in this population. Study 3: BT to diagnose LD is of limited usefulness in this population; further study in this area is not feasible.Methods. Separate studies address these objectives. Study 1 is a review of the literature using Medline. Study 2 is a double-blind, randomized, crossover, non-inferiority trial of HIV-infected individuals with CNID. Study 3 is a preplanned subgroup analysis of the participants in Study 2. Study 4 tests the correlations between various measures of diarrhea used in Study 2.Results. Study 1: In clinical trials of HIV-related diarrhea, the most frequent measures were stool frequency, form and duration. Validation of common measures of HIV-related diarrhea was poor. Study 2: The mean difference in stool weight after lactose ingestion compared to placebo was -41.3 g (upper 95% confidence limit less than the non-inferiority boundary). Study 3: The mean difference in stool weight between the two study periods in the LD group was statistically different but likely clinically unimportant compared to the lactase present group. The smallest sample size was 183 for a new study of the specificity of BT. Study 4: Subject self-report of stool frequency underestimated the results obtained prospectively. Models including both study day stool form and stool frequency best predicted diarrhea severity.
Notes: Adviser: Richard Glazier.

Thesis (Ph.D.)--University of Toronto, 2004.

Electronic version licensed for access by U. of T. users.

Source: Dissertation Abstracts International, Volume: 65-10, Section: B, page: 5068.