4 All tests All subjects Clinic recruits Neighborhood recruits Asymptomatic tests All subjects Clinic recruits Neighborhood recruits Parameter Time spent receiving care Hours Cost per hour Testing costs Home Clinic direct costs (clinician & test costs) 511 460 395 337 116 123 274 261 199 183 75 78 <2.5 <11 >30 <32 Clinic testing (n = 191) Home testing (n = 197) Clinic testing (n = 99) Home testing (n = 99) Clinic testing (n = 92) Home testing (n = 98) Clinic testing (n = 191) Home testing (n = 197) Clinic testing (n = 99) Home testing (n = 99) Clinic testing (n = 92) Home testing (n = 98) 3.7 16 25 49 Infectious Diseases in Obstetrics and Gynecology Table 3: Number of tests completed, testing costs, and cost-eﬀectiveness of the home screening intervention. Clinic Tests completed Cost per subject Home Total Per subject Direct Indirect Total Cost per additional test completed 2 254 1 119 1 135 0 173 0 77 0 96 513 714 396 456 117 258 274 434 199 260 75 174 2.7 3.6 4.0 4.6 1.3 2.6 1.4 2.2 2.0 2.6 0.8 1.8 132 147 197 198 62 96 71 87 99 110 40 64 166 145 248 212 78 78 89 82 125 115 51 49 298 292 445 409 141 174 160 169 224 225 91 113 — Cost saving — Cost saving — 24.50 — 12.51 — 2.16 — 23.13 Table 4: One-way sensitivity analysis, all subjects and all testing. Parameter values where the home testing intervention is more costly than clinic-based testing. Baseline value Home testing more costly occurred with home testing depended on the patient group and clinical situation studied, based on changes in clinic- based testing resulting from the intervention when STD de- tection is the same with either testing program. Cost savings were seen in clinic-recruited subjects, a group that utilized clinic services more frequently, due to decreases in clinic- based testing resulting from the availability of home test- ing. In subjects recruited from neighborhoods surround- ing the clinics, home testing was not cost saving, because of increased home testing without proportionate clinic test- ing reductions or STD detection improvements. When only asymptomatic tests were considered, home testing was again not cost saving. Finally, the indirect costs of seeking or receiv- ing care, that is, monetary costs for childcare, parking, and other expenses; time costs from missed work or school; and time donated by others were considerable and could present barriers to receiving recommended testing and care. As suggested by this analysis and by the DAISY study it- self, the decision to implement a home testing intervention for chlamydia and gonorrhea is more complex than merely seeking to maximize tests performed or to minimize costs. Home testing programs have been well demonstrated to in- crease testing volume [1–3], by decreasing some barriers to STD testing through the use of a relatively expensive test. Un- less direct costs incurred by individual clinics could be de- creased as a result of a home testing intervention, in times of budgetary limitations clinics would have no incentive or means to implement such an intervention. Indirect cost sav- ings (when the intervention is considered from the broader, societal standpoint) and the public health beneﬁts of in- creased testing suggest that ﬁnancial support for home test- ing would need to come from higher levels for these soci- etal beneﬁts to be obtained. For individual clinics with a high proportion of frequently utilizing patients, a home testing in- tervention could decrease the visit frequency by this patient group, increasing capacity for other needed services and pa- tient groups. In diﬀerent populations where care-related in- direct costs might be higher, for example, due to clinic inac- cessibility or unavailability, home testing might prove more useful from clinical and economic standpoints by increasing testing rates through decreasing individual disincentives for testing. Concerns about home testing decreasing necessary clinic visits appear to be unfounded [1]. Cost savings were not seen when only asymptomatic tests are considered, implying that home testing for screening pur- poses may not be economically favorable. However, the dis- tinction of symptomatic and asymptomatic testing might be somewhat artiﬁcial when a population is considered, since the availability of home tests could have beneﬁts beyond those of screening. For example, delays in seeking care when symptomatic are common, and the availability of home test- ing may allow infections to be diagnosed sooner, potentially decreasing untreated illness burden and PID risk. No diﬀer- ences in infection detection were seen between randomiza- tion groups in the DAISY study, where an urban population with relatively easy and frequent access to care was investi- gated; populations with less access could beneﬁt more from home screening. Finally, few screening interventions are cost saving, with some cost per health beneﬁt gained absorbed by society or payers based on the magnitude of screening costs