Table 3.

Summary of findings on patient preferences (key question 3)

Study designs	Outcome Studies; sample size	Findings	Certainty of the evidencea	What does the evidence say?
Preference-based using direct (n=3) and indirect (n=1) methods to derive health-state utilities	Infertility HSUV 3; 461 [96, 110, 113]	TTO range 0.76–0.91 (SD 0.25–0.34); VAS range 0.53–0.68 (SD 0.24–0.29); indirect 0.82 Best estimate of utility value = 0.80 (range 0.76–0.91)	Moderate	Based on utility values, the potential benefits from screening are probably of similar importance to people.
	Chronic pelvic pain HSUV 4; 733 [96, 99, 110, 113]	TTO range 0.69–0.85 (SD 0.29–0.38); VAS range 0.45–0.61 (SD 0.29–0.38); indirect 0.60 Best estimate = 0.76 (range 0.69–0.85)	Moderate
	Ectopic pregnancy HSUV 3; 461 [96, 110, 113]	TTO range 0.79–0.91 (SD 0.26–034); VAS range 0.55–0.73 (SD 0.21–0.25); indirect: out-patient 0.58 vs in-patient 0.23 with recuperation 0.60 (added to PID health state) Best estimate = 0.83 (range 0.79–0.91)	Low to moderate
	PID HSUV 3; 461 [96, 110, 113]	PID out-patient: TTO range 0.82–0.90 (SD 0.22–0.33); VAS range 0.62–0.76 (SD 0.17–0.24); indirect 0.63 PID in-patient: TTO range 0.82–0.88 (SD 0.27–0.36); VAS range 0.60–0.74 (SD 0.20–0.25); indirect IPNS 0.57 vs IPS 0.46 with OPAIP 0.83 Best estimate (majority treated as outpatient) = 0.86 (range 0.82–0.90)	Low to moderate
	Cervicitis HSUV 1; NR [96]	Indirect methods 0.90 (no measure of variance)	Low to moderate
	Rank order of outcomes based on QALY loss 4; 733 [96, 99, 110, 113]	Infertility > chronic pelvic pain >> ectopic pregnancy = PID = cervicitis Based on range of QALY losses ((1− best estimate of utility) × duration in years) for each health state: Infertility (0.20 × 10–30 years) = 2–6 QALY loss > chronic pelvic pain (0.24 × 5–10 years = 1.2–2.4 QALY loss) >> ectopic pregnancy (0.17 for 4 weeks =0.013 QALY loss) = cervicitis (0.10 × 4 weeks = 0.008 QALY loss) = PID (0.14 × 10–12 days = 0.004 QALY loss)	Low to moderate	Infertility and chronic pelvic pain may be considerably more important to females than ectopic pregnancy, PID, and cervicitis.
Survey (n=1) and qualitative studies (n=9) providing non-utility data	Relative importance of benefits vs harms Patients mainly considering rather than undergoing CT and NG screening 777 (7 studies)	Two studies of general-risk populations found that harms from stigma of a diagnosis and (less so) anxiety from testing may outweigh the potential benefits on their reproductive health (unspecified outcomes) and transmission [82, 83]. One study’s findings indicated that a fine balance may exist between a large potential for reduced transmission and several harms, from stigma from testing, anxiety about CT, and relationship distress [84]. The remaining four studies suggested that the potential benefits from reduced transmission and (less so) improved future reproductive health will outweigh the harms from anxiety and stigma when making decisions about screening [85, 87, 107, 112]. The relative importance placed on benefits may be higher for women.	Very low	Patients considering screening (mainly females) may place more importance on the potential benefits than on the harms from screening, but the evidence is very uncertain with indication of variability. Transmission as the only benefit considered may still lead to the same assessment, as would consideration of both transmission and future reproductive health.
	Relative importance of benefits vs harms Patients who have undergone CT screening 77 (3 studies)	The potential benefits for reducing infertility and/or transmission may outweigh any (transient and mild) harms from anxiety or stigma experienced from screening, except in those getting a diagnosis where the stigma (e.g., about transmitting to others in social network) and anxiety about infertility will likely become relatively more important [91, 102, 103]. It is unclear if the harms from a diagnosis would deter people in these studies from future screening. Because of being told about the uncertain course of CT infections and duration required to cause infertility [91, 102], many women who tested positive in two studies were significantly concerned about the possibility of being infertile and distressed by their unanswered questions. One of the studies found that the harm from stigma after a diagnosis (or an anticipated one) was the main driver for regular repeat testing, to alleviate the feelings [103].	Very low	Patients who have undergone screening, and are not diagnosed with CT, may place more importance on the benefits than on the harms, but the evidence is very uncertain.

Abbreviations: CT Chlamydia trachomatis, HSUV health-state utility value, IPNS in-patient nonsurgical, IPS in-patient surgical, NG Neisseria gonorrhoeae, OPAIP out-patient after in-patient, PID pelvic inflammatory disease, QALY quality-adjusted life year, SDstandard deviation, TTO time trade off, VAS visual analog scale

^a Reasons for ratings are explained in Additional file 6