Background
Impact of the infections
Screening for CT and NG
Purpose of review
Methods
Key questions
-
KQ1: What is the effectiveness of screening compared with no screening for chlamydia and/or gonorrhea in non-pregnant sexually active individuals?
-
KQ2: What is the comparative effectiveness of different screening approaches for chlamydia and/or gonorrhea in non-pregnant sexually active individuals?
-
KQ3: What is the relative importance that people place on the potential outcomes from screening for chlamydia and/or gonorrhea?
Eligibility criteria
Key questions 1 and 2
Key question 3
Searching the literature and selecting studies
Data extraction and analysis
Risk of bias assessments
Assessing the certainty of the evidence on outcomes across the studies
Interpretations
Results
Effectiveness of screening versus no screening (key question 1)
Benefits
Author, year Country | Design, intensity, sample size, risk of bias | Screening rates in intervention group (IG), rates of testing outside of study (IG; control group [CG]) | Sex and age | Baseline CT positivity of tested, all sexually active (Y/N) | Recruitment | Screening approach; CT vs CT and NG; location, test, and person testing; re-testing; co-interventions | Outcome assessment Incidence of PID in CG Follow-up durations |
---|---|---|---|---|---|---|---|
Randomized controlled trials | |||||||
Andersen et al. 2011 [59] Denmark | RCT 1 screen offered 15,459 ROB: unclear (detection bias) | 29% IG 9.0% vs CG 9.4% during 3 mos study period | F 21–24 yrs | 7.1%; N | Population-based via mailed kits | Universal; CT; home-collected vaginal pipette, with NAAT; 70% re-tested; none | PID: hospital discharge ICD codes or doxycycline prescriptions (only used for PID in Denmark; 33% by GPs). Incidence in CG 0.65%. Follow-up duration, 1 yr EP and infertility: hospital discharge ICD codes. Follow-up duration, 9 yrs |
Garcia et al. 2012 [60] Brazil | RCT cluster Screening offered every 8 wks over 3 yrs 20 cities with >50,000 inhabitants; follow-up survey using sampling at random sites at baseline (3732) and after 4 yrs (4156) ROB: unclear (performance bias) | NR (interviewed FSWs 48,207 times during 20 8-wk cycles) NR | F >14 yrs Mean 24.5 yrs | 15.5% CT, 2.4% NG; Y | Outreach via mobile teams | Universal; CT and NG (and other STIs); mobile site self-collected vaginal swabs with NAAT; re-testing NR but frequent visits; multi-faceted syndromic management in general population and clients of FSWs; condom promotion with motivational interviewing and free condoms; peer education | Estimated population prevalence in FSWs using surveys (>99% of eligible enrolled) at random FSW sites. Follow-up duration, 3.5 yrs |
Hocking et al. 2018 [8] Rural Australia | RCT cluster 3 annual screens offered 52 clusters (130 clinics of >500 16–29 yr olds) ROB: unclear (performance and attrition biases) | 24% ≥1 times over 3 yrs (8.2% pre-trial yr to 20% at 25–36 mos) IG NR; CG rates increased from 8.2% pre-trial to 12.9% (stable over trial) | F and M 16–29 yrs | 10% in those testing; 4.8% (4.5% females and 5.5% males) in prevalence surveys; Y | Primary care (clinic attenders) | Opportunistic; CT; in-clinic patient-collected vaginal or urine with NAAT; approx. 25% re-testing each year; multi-faceted with provider reminders, incentives, education, payments and feedback, and patient recall systems | Clinic PID: cumulative incidence in clinics for women 16–33 with at least one clinic visit during intervention period. Criteria provided to all providers but not blinded. Incidence in CG 0.4%. Hospital PID: ICD codes for all 15–34 yr olds living in each cluster. Incidence in CG 0.4%. Not used for main analysis because of low ascertainment and difference in trial and hospitalized populations Estimated population prevalence (in clinic attenders): Using surveys of consecutive clinic attenders (70% response) before randomization and at end of trial (difference in change from baseline) Follow-up duration for all outcomes: 3 yrs |
Hodgins et al. 2002 [12] Nunavik region in Northern Quebec | RCT cluster 1 screen offered 12 communities in Nunavut (2320, 15–39 years) ROB: high (incomplete outcome data with reported rates based on low uptake; multiple unclear domains) | 31% NR | F and M All; focus on 15–39 yrs | 7%; Y | Outreach via community | Universal CT; home urine sampling with PCR; re-testing NR; intensive community health education program | Estimated population prevalence via reported rates over past yr in communities. Follow-up duration, 1 yr |
Klovstad et al. 2013 [98] Norway | RCT 1 screen offered 41,519 (10,000 IG) ROB: low | IG 14% (85% of 16.5% testing via study or healthcare system) IG 2.5%, CG 3.4% | F and M 18–25 yrs | IG 6.3% vs 11.6%; N | Population-based register via mailed invitations with screening kits (no reminders) | Universal; CT; home urine sampling via mailed kit via NAAT; N; N | Treatment for CT: national prescription database (filled at least one prescription for (azithromycin, doxycycline, erythromycin, lymecyklin, amoxicillin) within 30 days following a positive test result. Follow-up duration, 3 mos |
Oakeshott et al. 2010 [28] London, UK | RCT 1 screen 2529 ROB: low | 100% 22% both groups (43% of those CT+ in CG) | F 16–27 (mean 21) yrs | 5.4%; Y | Outreach at common rooms, lecture theaters, and student bars at universities and further education colleges in London | Universal; CT; outreach site self-collected vaginal swabs with NAAT; re-testing NR; informed of risks of CT infection | PID: Any report by participants or their providers about signs and symptoms or dx, looked to medical records in general practitioners, hospitals, family planning clinics, and genitourinary medicine clinics. Used criteria for all cases, but medical records sometimes incomplete. Incidence in CG 1.8%. Follow-up duration, 1 yr |
Ostergaard et al. 2000 [105] Denmark | RCT cluster 1 screen 17 schools (IG 928 vs CG 833) ROB: high (attrition [>50%] and lack of cluster analysis), unclear for other domains except allocation concealment | IG 93% vs CG 7.5% IG 29% and CG 36% (p=0.04) | F ≥15 yrs in high school (9% ≥19 yrs) | IG 5% vs CG 7.9%; Y | Outreach in schools with provision of home kits or invitation/reminder to go to general practitioner or STI clinics | Universal; CT; home sampling using vaginal pipette and NAAT vs. in-clinic swab with EIA; re-testing NR; information about consequences | PID: Self-reported at follow-up questionnaire, with confirmation in registration for prescriptions. Incidence in CG 4.1%. Follow-up duration, 1 yr |
Scholes et al. 1996 [108] Washington, USA | RCT 1 screen offered to selected females 2607 ROB: unclear (selection, performance and detection biases) | 64% NR | F 18–34 yrs; 81% ≤24 yrs | 7%; Y | Primary care using telephone recruitment with questionnaire for high-risk considering race, douching, and ≥2 sexual partners in the preceding 12 months; married women excluded | Universal; CT; in-clinic; clinician-collected cervical swabs (EIA or culture); re-testing NR; none | PID: Self-report signs, symptoms, dx; medical records, hospital discharge, and pharmacy records. Dx had to be recorded and considered “clinical” (37 of 142 reported PID confirmed) but no specific criteria provided. Incidence in CG 2%. Follow-up duration, 1 yr |
Senok et al. 2005 [109] UK | RCT postal and opportunistic vs usual care over 4-month period 476 ROB: high for attrition bias; unclear for selection and detection | Opportunistic 21%; postal 48%; UC 0%; NR | F 16–30 yrs; mean 24 yrs | Opportunistic 14% Postal 5% Usual care NR; N | Letters from general practice lists | Universal opportunistic and postal; CT; NR; no; incentives to providers at practices | Treatment for CT: clinic records. Follow-up duration, 4 mos |
van den Broek et al. 2012 [9] Netherlands | RCT stepped-wedged cluster 3 annual offered 190 clusters with 317,304 people in three regions ROB: unclear for performance and detection biases and incomplete outcome data (prevalence); high for incomplete outcome data (positivity) | 16% (1st round), 10% (3rd round) (vs 13% in controls) NR | F and M 16–29 yrs | 4.3% (7.1% in <20 yr olds); NR | Population-based with postal invite to request sampling kit via internet | Universal; CT; home with urine for males and vaginal swab or urine for females; kits for re-testing sent 6 mos after CT+ (uptake NR); none | Estimated population prevalence using data from positivity with extrapolation to sexually active population of same ages in communities. Follow-up duration, 2 yrs |
Controlled clinical trials | |||||||
Clark et al. 2001 [88] USA (Army recruits to South Carolina) | CCT 1 screen 28,074 ROB: high (selection and detection bias) | 100% NR | F 17-39 yrs; 88% ≤25yrs | 9.1%; N (93% of IG but higher and unknown for CG) | Community outreach via non-health Army training examination center | Universal; CT; on-site self-collected urine with NAAT; re-testing NR; education on STDs | PID, EP, infertility: Hospital discharge records. Incidence in CG 5.1/1000 PY (0.8%), 1.9/1000 PY and <0.01/1000 PY. Follow-up duration: mean 1.5 yrs |
Cohen et al. 1999 [89] Louisiana, USA | CCT Bi-annual screening offered over 2.5 years (CG invited in 3rd year with 1 test period) 5907 from 3 IG and 5 CG schools ROB: high for selection, performance (11–53% testing outside of trial), attrition and other (no cluster adjustment) biases | 83% at least once; annually, 52 to 65% IG and CG 11% grade 9 and 53% grade 12, males ~20% | F and M Grades 9–12 | CT 11.5% females (8.7% in grade 9s vs 14% in grade 12s), 6.2% males NG 2.5% females, 1.2% males (similar across ages) N | Community health in high school health centers | Universal; CT and NG; on-site urine with NAAT; re-testing NR but bi-annual testing; information about risks and consequences | CT positivity in screening eligible students, who participated in screening, in IG after year 2 (5 tests offered) and CG (offered screening after year 2 in IG); Follow-up duration, 2.5 yrs NG positivity in screening eligible students, who participated in screening, in IG after year 1 (3 tests offered) and CG (offered screening after 1 year of NG testing added in 2nd year of study). Follow-up duration, 1.5 yrs |
Observational studies | |||||||
Sufrin et al. 2012 [111] California, USA | Retrospective cohort 1 screen 57,728 ROB: moderate (selection bias with some adjustment) | 100% NA | F 14–49 yrs; mean 32 yrs (non-screened 7 yrs older) | NR; Y | Primary care | Unknown but assume some form of risk assessment for screening same day or up to 1 year before IUD insertion; CT; in-clinic but unknown test and methods; re-testing NR; none | PID after IUD insertion: Health Maintenance Organization database ICD plus antibiotic pharmacy dispensed, with record review in 10% random sample if discordant; closed system. No specific criteria. Incidence in CG 0.36%. Follow-up duration, 3–15 mos (3 mos after IUD insertion but up to 15 mos from screen) |
Low et al. 2006 [101] Sweden | Retrospective cohort 48% screened once, 22% twice, 30% ≥3 tests over 10 yr 43,715 ROB: moderate (selection bias with some adjustment) | 100% NA | F 15–24 yrs | NR (11.5% at some time during follow-up); N | Population-based | Opportunistic used in county; CT; in-clinic sampling NR with culture; none | PID, EP, infertility: hospital discharge in-(all yrs) and out-(last 6 yrs) patient. No criteria. Incidence in CG 2.9%, 1.9%, 3.1% over 10 yrs. Follow-up duration, 10 yrs |
Outcome | Study approach | Assumed population riska | Studies; sample sizeb | Follow-up (yrs) | Absolute effects | Certaintyc | What happens? |
---|---|---|---|---|---|---|---|
PID MID 2.5 fewer or more per 1000 | Offer of universal CT screening, annually for 1–3 years | Study data | 1–3 | 0.1 more in 1000 (2.1 fewer to 1.5 more) | Low to moderate | Little-to-no difference | |
General | 0.3 more in 1000 (7.6 fewer to 11 more) | Very low | Little-to-no difference | ||||
High | 0.5 more in 1000 (13.1 fewer to 18.7 more) | Very low | Little-to-no difference | ||||
Offer of 1 universal CT screen—selected population | Study data | 1 RCT; 2607 [108] | 1 | 11.8 fewer per 1000 (2.3 to 16.3 fewer) | Low to moderate | Small reduction | |
General | 15.4 fewer per 1000 (3 to 21.3 fewer) | Low to moderate | Small reduction | ||||
High | 26.8 fewer per 1000 (5.2 to 37.1 fewer) | Low | Moderate reduction | ||||
Acceptors of 1 universal CT screen | Study data | 1 | 3.7 fewer per 1000 (7.1 fewer to 0.7 more) | Low | Small reduction | ||
General | 5.7 fewer per 1000 (10.8 fewer to 1.1 more) | Low | Small reduction | ||||
High | 9.9 fewer per 1000 (18.8 fewer to 1.9 more) | Very low to low | Moderate reduction | ||||
Ectopic pregnancy MID 1 fewer or more per 1000 | Offer of 1 universal CT screen | General | 1 RCT; 15,459 [59] | 9 | 0.20 more per 1000 (2.2 fewer to 3.9 more) | Very low | Little-to-no difference |
Acceptors of 1 universal CT screen | High | 1 CCT; 28,074 [88] | 1.5 | 0.63 more per 1000 (0.76 fewer to 2.8 more) | Very low | Little-to-no difference | |
Infertility—female MID 1 fewer or more per 1000 | Offer of 1 universal CT screen | General | 1 RCT; 15,459 [59] | 9 | 4.2 more per 1000 (1.7 fewer to 11.2 more) | Very low | Very uncertain |
Acceptors of 1 universal CT screen | High | 1 CCT; 28,074 [88] | 1.5 | 0.15 fewer per 1000 (0.37 fewer to 0.88 more) | Very low | Very uncertain | |
Transmission of CT—prevalence MID 5 and 10 fewer or more per 1000 | Offer of universal CT screening—annually for 1–3 years | General—both sexes | 1–3 | 3 fewer per 1000 (11.5 fewer to 6.9 more) | Low (5 fewer per 1000) Low to moderate (10 fewer per 1000) | Little to no difference | |
General— females | 2–3 | 4.1 fewer (13.5 fewer to 9.75 more) | Very low to low (5 fewer per 1000) Low (10 fewer per 1000) | Little-to-no difference | |||
General— males | 2-3 | 7.2 fewer (18.9 fewer to 8.6 more) | Very low (5 fewer per 1000) Very low to low (10 fewer per 1000) | Very uncertain | |||
Offer of universal CT and NG screening—frequent screening over 2.5–4 years | High—both sexes | 1 cluster CCT; 3803 [89] | 2.5 | 26 fewer cases in 1000 (65 fewer to 68 more) | Very low (both thresholds) | Very uncertain | |
High—females | 2.5–4 | 34.3 fewer per 1000 (4 to 58 fewer); NNS 29 (17 to 250) | Low to moderate (both thresholds) | Moderate reduction | |||
High—males | 1 CCT; 1830 [89] | 2.5 | 31 fewer per 1000 (55 fewer to 52 more) | Very low (both thresholds) | Very uncertain | ||
Transmission of NG—prevalence MID 5 and 10 fewer or more per 1000 | Offer of universal CT and NG screening—frequent screening over 2.5–4 years | High—both sexes | 1 CCT; 3765 [89] | 2.5 | 3 fewer in 1000 (5 fewer to 87 more) | Very low | Very uncertain |
High—females | 2.5–4 | 5–7 fewer per 1000 | Very low to low | Moderate reduction | |||
High—males | 1 CCT; 1826 [89] | 2.5 | 0.4 fewer in 1000 (10 fewer to 117 more) | Very low | Very uncertain |
Harms
Comparative effectiveness of different screening strategies (key question 2)
Patient values and preferences: relative importance of outcomes (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 | 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 | 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 | 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 | 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 | 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. |