Management of the low-grade abnormal Pap smear: What are women’s preferences?

The management of women who have low-grade cytologic abnormalities—including atypical squamous cells (ASC) and low-grade squamous intraepithelial lesions (LSIL)—is controversial.^1-4 Without strong evidence favoring a single approach, some clinicians recommend immediate colposcopy to obtain a definitive diagnosis and to exclude the presence of a high-grade lesion, while others recommend observation with serial Pap smears, given the tendency for many low-grade lesions to regress spontaneously.^5,6 Immediate colposcopy has the advantage of giving a patient a relatively rapid assessment of the nature and extent of her cervical dysplasia; however, the procedure is uncomfortable, and overall management may not be affected. Observation with serial Pap smears may avoid an invasive procedure, but it may also cause anxiety as time passes without a definitive diagnosis.

Eliciting and understanding patient preferences is an important part of clinical decision making. The clinician provides the best available information on the probability of clinical outcomes and the implications of each for the patient’s health. But only the patient knows what these outcomes mean to her well-being (also called “utility”).

Given the clinical disagreement over how to proceed with abnormal ASC and LSIL Pap smear results, the decision should be influenced by a patient’s preference, informed by knowledge of outcomes and costs of alternative approaches. It is unclear which approach women prefer, and whether women’s preferences for specific protocols are associated with sociodemographic characteristics. To understand better how women weigh these trade-offs, we evaluated the preferences of a diverse group of women for contrasting management approaches to the evaluation of a hypothetical low-grade abnormal Pap smear result.

Methods

Study population

Study participants were recruited from the waiting rooms of 5 family planning clinics in Northern California’s Central Valley. Women were eligible for the study if they were 18 years of age or older, or, if minors, they were emancipated and could thus provide informed consent. Potential subjects were excluded if they spoke neither English nor Spanish or if they had never had a Pap smear. The study protocol and informed consent procedures were reviewed and approved by the University of California, Davis, Human Subjects Committee.

Instruments and outcome measures

Interviews were conducted in English or Spanish. Information regarding demographic characteristics, level of education, past experiences with abnormal Pap smears and cervical cancer, and self-rated religiosity was collected with a self-administered questionnaire. The primary outcome measures were utilities (quantified preferences for specific health states) for 6 different scenarios. These were assessed by the standard gamble (SG) method, described in more detail below.⁷

Possible utility scores range from 0 to 1. A score of 0 represents immediate death; a score of 1 represents full (or ideal) health for the rest of one’s life. Because the scenarios under consideration in this study did not involve any meaningful level of risk of death, we expected utility scores for the scenarios to cluster toward the upper end of the scale. As a result, a measurement instrument based on an “immediate death” versus “full health” scale would be unable to discriminate between different scenarios. To avoid this problem, a scale was used in which the lower end point was a non-death state unambiguously less preferred than each of the scenarios under consideration.⁸ We used “invasive cervical cancer requiring hysterectomy” as the lower end point (utility of 0) contrasted with “full health with all normal Pap smears” (utility of 1) to generate the original score (SG Dys). In a separate standard gamble, subjects rated invasive cervical cancer versus immediate death (SG Ca), so that all utilities could be converted to the standard scale, using the formula: (1 – SG Ca) (SG Dys) + SG Ca.

The 6 scenarios rated in the study are shown in Table 1. The scenarios represent 3 sets of progressively more invasive interventions for a low-grade abnormal Pap smear: (1) resolution, representing spontaneous regression with treatment not required; (2) a low-grade abnormality requiring treatment with cryotherapy; (3) a more severe abnormality requiring a cervical cone biopsy. Following either spontaneous resolution or treatment, all scenarios assumed the abnormality was resolved. For each of the 3 results, a management strategy based on observation with serial Pap smears was applied in 1 instance, and a strategy of early colposcopy was applied in the other instance, resulting in 6 different pathways to the ultimate outcome; a normal Pap smear. The time frame for these scenarios was 18–36 months.