Evaluation of a volunteer sample in nasopharyngeal colonization surveys for Streptococcus pneumoniae in rural Alaska

Abstract

Our study provides further empirical evidence that selection bias should be considered when designing studies. However, a volunteer sample provided internal consistency for comparison of our main study outcomes across time.

Risk Factors for Pneumococcal Colonization of the Nasopharynx in Alaska Native Adults and Children

“…Thus, the overall prevalence of colonization from this study may be somewhat higher than the actual prevalence in these regions. This result is consistent with an analysis of this surveillance population in the past [35], which showed bias toward households with more children and more frequent clinic visits. The large sample sizes in this analysis provided high power to detect relatively small effect sizes.…”

Indirect Effect of Conjugate Vaccine on Adult Carriage ofStreptococcus pneumoniae:An Explanation of Trends in Invasive Pneumococcal Disease

“…They were, however, representative of typical rural villages in that ∼95% of residents were Alaska Native people, had similar economic and cultural factors, and had similar health care opportunities. Analysis comparing participants in the present study with nonparticipants demonstrated that participants were younger, used the health care services at the clinic more frequently, and used more antibiotics than did nonparticipants [30]. However, these differences were similar across all years of the study, which allows for comparability between study years.…”

Serotyping of Streptococcus pneumoniae Isolates from Nasopharyngeal Samples: Use of an Algorithm Combining Microbiologic, Serologic, and Sequential Multiplex PCR Techniques

“…Studies of pneumococcal colonization began in Alaska in an effort to understand how antimicrobial use affects the carriage of nonsusceptible pneumococci (5,11,12). These studies continued after introduction of the heptavalent pneumococcal conjugate vaccine (PCV7) to monitor carriage of PCV7 serotypes.…”