Abnormal outcomes following cervical cancer screening: event duration and health utility loss.
BACKGROUND
For decision analytic models, little empirical data are available from which to model the amount of time women spend with various cervical cytologic and histologic diagnoses following an abnormal Pap smear or the associated loss in quality-adjusted life-years (QALYs).


METHODS
The authors retrospectively examined administrative and cytopathology data for women with abnormal routine cervical smears within the Kaiser Permanente Northwest (Portland, OR) health plan during 1998. Data were examined through the conclusion of follow-up, with final outcomes categorized as cervical intraepithelial neoplasia (CIN) grades 1 to 3 (n = 201) or a false-positive result (n = 722) if no CIN or cancer was detected on follow-up. CIN outcomes were assigned according to the initial grade of dysplasia observed during the care episode in the primary analysis. The number of months spent with various cytologic and histologic diagnoses during the course of follow-up was tabulated, and utility weights were assigned using data from a prior study reporting time tradeoff scores for cervical health states.


RESULTS
The average total duration of follow-up was between 18 and 22 months for women with CIN, compared with 10 months for a false-positive Pap smear. The number of months spent with either an abnormal cytologic or histologic diagnosis was greater (P = 0.01) for women with CIN 1 (12.6 months) than CIN 3 (9.2 months), although this relationship was reversed for time spent receiving negative follow-up Pap smears and biopsies to rule out the presence of CIN and cancer. Total QALY losses per episode of care were estimated to be 0.11 for all 3 grades of CIN and 0.04 for a false-positive Pap smear.


CONCLUSIONS
The health and psychosocial burdens associated with follow-up for abnormal Pap smears translate into tangible QALY losses in a decision analytic context, with women receiving many months of follow-up and a variety of cytologic and histologic diagnoses over the course of a care episode.
Insinga
Ralph P
RP
Department of Health Economic Statistics, Merck Research Laboratories, North Wales, Pennsylvania, USA. Ralph_insinga@merck.com
Glass
Andrew G
AG
Myers
Evan R
ER
Rush
Brenda B
BB
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D065006:Papanicolaou Test; D019057:Quality-Adjusted Life Years; D012189:Retrospective Studies; D013997:Time Factors; D002583:Uterine Cervical Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology*; D014626:Vaginal Smears; D002578:Uterine Cervical Dysplasia / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology*