RESUMEN
BACKGROUND: To develop content validity of a comprehensive patient-reported outcome (PRO) measure following current best scientific methodology to standardize assessment of influenza (flu) symptoms in clinical research. METHODS: Stage I (Concept Elicitation): 1:1 telephone interviews with influenza-positive adults (≥18 years) in the US and Mexico within 7 days of diagnosis. Participants described symptom type, character, severity, and duration. Content analysis identified themes and developed the draft Flu-PRO instrument. Stage II (Cognitive Interviewing): The Flu-PRO was administered to a unique set of influenza-positive adults within 14 days of diagnosis; telephone interviews addressed completeness, respondent interpretation of items and ease of use. RESULTS: Samples: Stage I: N = 46 adults (16 US, 30 Mexico); mean (SD) age: 38 (19), 39 (14) years; % female: 56%, 73%; race: 69% White, 97% Mestizo. Stage II: N = 34 adults (12 US, 22 Mexico); age: 37 (14), 39 (11) years; % female: 50%, 50%; race: 58% White, 100% Mestizo. SYMPTOMS: Symptoms identified by >50%: coughing, weak or tired, throat symptoms, congestion, headache, weakness, sweating, chills, general discomfort, runny nose, chest (trouble breathing), difficulty sleeping, and body aches or pains. No new content was uncovered during Stage II; participants easily understood the instrument. CONCLUSIONS: Results show the 37-item Flu-PRO is a content valid measure of influenza symptoms in adults with a confirmed diagnosis of influenza. Research is underway to evaluate the suitability of the instrument for children and adolescents. This work can form the basis for future quantitative tests of reliability, validity, and responsiveness to evaluate the measurement properties of Flu-PRO for use in clinical trials and epidemiology studies.
Asunto(s)
Gripe Humana/fisiopatología , Evaluación del Resultado de la Atención al Paciente , Encuestas y Cuestionarios , Adulto , Tos , Femenino , Cefalea , Humanos , Masculino , México , Dolor , Reproducibilidad de los ResultadosRESUMEN
OBJECTIVE: Immunization against rotavirus has been proposed as the most cost-effective intervention to reduce the disease burden associated with this infection worldwide. The objective of this study was to determine the dose response, immunogenicity, and efficacy of 2 doses of an oral, attenuated monovalent G1[P8] human rotavirus vaccine in children from the same setting in Mexico, where the natural protection against rotavirus infection was studied. METHODS: From June 2001 through May 2003, 405 healthy infants were randomly assigned to 1 of 3 vaccine groups (virus concentrations 10(4.7), 10(5.2), and 10(5.8) infectious units) and to a placebo group and were monitored to the age of 2 years. The vaccine/placebo was administered concurrently with diphtheria-tetanus toxoid-pertussis/hepatitis B/Haemophilus influenzae type b vaccine at 2 and 4 months of age. After the administration of the first vaccine/placebo dose, weekly home visits to collect information regarding infant health were conducted. Stool samples were collected during each gastroenteritis episode and tested for rotavirus antigen and serotype. RESULTS: The vaccine was well tolerated and induced a greater rate of seroconversion than observed in infants who received placebo. For the pooled vaccine groups, efficacy after 2 oral doses was 80% and 95% against any and severe rotavirus gastroenteritis, respectively. Efficacy was 100% against severe rotavirus gastroenteritis and 70% against severe gastroenteritis of any cause with the vaccine at the highest virus concentration (10(5.8) infectious units). The predominant infecting rotavirus serotype in this cohort was wild-type G1 (85%). Adverse events, including fever, irritability, loss of appetite, cough, diarrhea, and vomiting, were similar among vaccinees and placebo recipients. CONCLUSION: This new oral, live, attenuated human rotavirus vaccine was safe, immunogenic, and highly efficacious in preventing any and, more importantly, severe rotavirus gastroenteritis in healthy infants. This vaccine produced comparable protection to natural infection.
Asunto(s)
Gastroenteritis/prevención & control , Infecciones por Rotavirus/prevención & control , Vacunas contra Rotavirus/administración & dosificación , Administración Oral , Relación Dosis-Respuesta Inmunológica , Método Doble Ciego , Femenino , Estudios de Seguimiento , Gastroenteritis/epidemiología , Gastroenteritis/inmunología , Humanos , Lactante , Masculino , México/epidemiología , Estudios Prospectivos , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/inmunología , Vacunas contra Rotavirus/inmunología , Vacunas Atenuadas/administración & dosificación , Vacunas Atenuadas/inmunologíaRESUMEN
The WHO recommends exclusive breast-feeding (EBF) for the first 6 mo of life to decrease the burden of infectious disease. However, some are concerned about the effect of EBF >6 mo on iron status of children in developing countries in which anemia is prevalent. This study examines the risk of anemia in relation to the duration of EBF and maternal anemia in a birth cohort studied between March 1998 and April 2003. All infant birth weights were >or=2.2 kg. All mothers received home-based peer counseling to promote EBF. Infant feeding data were collected weekly. Nurses measured hemoglobin (Hb) values every 3 mo. Hb was measured in 183 infants at 9 mo of age. Anemia at 9 mo was defined as a Hb value <100 g/L. EBF was defined by WHO criteria and ranged in duration from 0 to 31 wk. At 9 mo, Hb (mean +/- SEM) was 114 +/- 0.9 g/L; 23 children (12.5%) had Hb levels <100 g/L. EBF >6 mo, but not EBF 4-6 mo, was associated with increased risk of infant anemia compared with EBF <4 mo (odds ratio=18.4, 95% CI=1.9, 174.0). Maternal anemia was independently (P=0.03) associated with a 3-fold increased risk of infant anemia. These associations were not explained by confounding with other maternal or infant factors. By linear regression, a lower infant Hb at 9 mo was associated with increased EBF duration among mothers who had a history of anemia (beta=-0.07, P=0.003), but not among mothers with no history of anemia. Infants who are exclusively breast-fed for >6 mo in developing countries may be at increased risk of anemia, especially among mothers with a poor iron status; greater attention to this issue is warranted.