Practice recommendations
- Gel should be considered a viable option in obtaining Pap smears to ease insertion, minimize discomfort, and perhaps help maintain regular interval sampling compliance. Physicians choosing to use gel should be careful to apply only a thin layer to the outer blades of the speculum.
- Because approximately two thirds of false-negative smears are related to inadequate sampling, be sure to obtain cells from the transformational zone, where cancer is known to develop.
The medical literature generally recommends moistening the speculum with water for performance of a Papanicolaou (Pap) test, because gel lubricants interfere with specimen analysis and assessment of vaginal secretions.1,2 After an extensive literature search, we found little information that identified or substantiated the type or frequency of interference or distortion in analysis or assessment with regard to gel lubricants on cervical cytologic evaluation. The only study of gel lubricant use that we found recommended further study because surprisingly few Pap smears are rendered inadequate despite the high prevalence of gel use.3
Due to these findings and the lack of literature substantiating interference or distortion with gel lubricants, we investigated whether there is a difference in Pap smear obscuration rates with gellubricated vs water-lubricated speculum samples.
Methods
Target population
The target population consisted of all women who received Pap smears between 1995 and 1999 at the University of Tennessee Health Sciences Center HealthPlex Family Medicine Residency Program in Memphis, Tennessee. Pap smears were obtained by resident physicians in the Department of Family Medicine, University of Tennessee Health Science Center. The specific technique used by the residents was left to their discretion and each was asked to describe the usual use of lubricants.
More than 4169 Pap smears were identified via Current Procedural Terminology codes (A88141, A88155, A88164, and/or A88167). Of these, 649 charts were selected by using every sixth record. From those selected, 615 contained adequate information to be included in the study.
Data collection
We gathered medical record data by using a retrospective review of medical records, including the medical record number, date of birth, date of service, provider performing pelvic examination or obtaining cervical cytology smear, identification of the laboratory processing and reporting each cytology report, and insurance coverage (Medicare, private, self-payer, and TennCare/ Medicaid). Cervical cytology report information retrieved included sample adequacy (satisfactory or unsatisfactory), whether the sample was identified as obscured, and whether obscuration was caused by blood.
We also collected data from the medical record on potential confounders, including socioeconomic status (determined by insurance source) and reproductive status (currently pregnant, menopausal, or posthysterectomy). Medical records containing incomplete documentation of any portion of the review criteria were excluded.
Analysis
Statistical analysis was completed with SAS 8.1. Simple χ2 analysis was used where appropriate to demonstrate associations. A stepwise regression model was considered, but none of the χ2 statistics were significant, which eliminated the need for a modeling procedure.
Results
Of the 615 participants, 50 were pregnant, 49 were menopausal, and 42 had undergone a hysterectomy. By matching clinicians’ survey responses to the cytology specimens they collected, we determined that 379 were acquired with water, 81 with gel, and 155 without lubricant.
We reviewed cytology reports for the documented level of adequacy, the presence of any obscuration, and the type of obscuration (see Table). for cytology findings). All 27 obscured and 4 inadequate specimens (5% of the 615 cytology reports reviewed) were reported among women who were pregnant, menopausal, or posthysterectomy. Menopausal women accounted for 89% (24) of obscured specimens and 100% (4) of inadequate specimens. Within the menopausal group, 63% (15) of the specimens were obscured by blood and 37% (9) were obscured by “other.” The term “other” was not defined further or explained on any cytology report. The 5 laboratories reporting obscuration by “other” were contacted, and all reported that this term defines obscuration by nonblood contaminants. Pregnant women accounted for 7% (2) of the obscured specimens, with 1 obscured by blood and 1 obscured by “other.” Women identified as posthysterectomy contributed 4% (1) of the obscured specimens; it was reported as obscured by “other.”
Reports identifying obscured or inadequate specimens and socioeconomic status were also cross-tabulated against type of lubricant used in consideration for possible bias. The outcome showed no identified indication.
No statistically significant difference was found in the likelihood of specimen obscuration or adequacy vs inadequacy between water, gel, or no lubricant. The occurrence of obscuration was lower with the use of water lubricant (3.2%) than with gel lubricant (6.2%) or no lubricant (6.5%). However, this difference was not statistically significant (P<.20).