Patient self-collection of group B streptococcal specimens during pregnancy

J Am Board Fam Med. Mar-Apr 2009;22(2):136-40. doi: 10.3122/jabfm.2009.02.080011.


Objectives: In the United States, universal screening for group B streptococcal (GBS) colonization is recommended at 35 to 37 weeks' gestation. Previous studies have shown equivalent detection rates for GBS when women receive uniform instruction about specimen collection. It is unclear if these results would hold among patients with limited education given minimal, nonuniform instruction about collection technique.

Methods: A retrospective analysis of GBS culture results for physicians who practice universal patient self-collection of specimens were compared with GBS culture results for physicians who personally routinely collect the specimens at 2 sites within a community health center network. For self-collection, medical assistant staff provided minimal instruction to patients about collection technique and without a protocol. Patients in both groups were primarily Hispanic and of lower socioeconomic status.

Results: Patient self-collection occurred in 293 of 800 specimens (36.6%). GBS was detected in 13.31% of patient self-collected samples and 10.65% of physician-collected specimens (relative risk, 1.25; 95% CI, 0.85-1.84). The study had 90% power to detect a 10% difference in colonization rates.

Conclusions: Patient self-collection with minimal instruction is not inferior to physician collection of specimens at detecting GBS colonization in a majority Hispanic population of lower socioeconomic status.

MeSH terms

  • Colorado
  • Female
  • Hispanic or Latino
  • Humans
  • Patient Education as Topic
  • Patients*
  • Pregnancy
  • Retrospective Studies
  • Self Care*
  • Social Class
  • Specimen Handling*
  • Streptococcal Infections / diagnosis
  • Streptococcus agalactiae / growth & development*
  • Streptococcus agalactiae / isolation & purification*
  • Vagina / microbiology