Table 3.

Approximate costs of outcomes of the campaign, Break the Chains (BTC), Switzerland, March to May 2015

Outcomes	Outcome measure (data source)	Estimated outcomes at the MSM population level	Campaign costs*/estimated outcome
Encounter	BTC 2015 outreach contacts/conversations with MSM, clicks on the campaign website†	33 833	USD PPP 14
To reach one MSM	MSM who heard about BTC 2015 (58.4%, postcampaign survey)	37 376–52 560‡	USD PPP 9–13
One MSMwr adopts a risk reduction strategy in April 2015	MSM at risk who used a risk reduction strategy in April 2015 (13.8%, postcampaign survey§)	8832–13 248‡	USD PPP 36–55
One MSMwr adopts an HIV risk reduction strategy because of the campaign	MSMwr who adopted an HIV risk reduction strategy in April and maintained it until HIV testing in May because of the BTC campaign (2.8%, postcampaign survey¶)	1792–2688‡	USD PPP 181–272

*Total campaign costs were USD PPP 488 984 (incl. direct USD PPP 474 019 and costs of non-market items USD PPP 14 965, as well as the costs for the HIV test price reduction USD PPP 29 473; CHF 603 896; purchasing power parity conversion rate for the year 2015: 1 CHF=1.235 USD PPP). See online supplementary table S3 for more detailed explanation.

†9746 (28.8%) of the 33 833 encounters are web clicks (no information available if web users are belonging to the target population), data from Swiss AIDS Federation.

‡Extrapolation of the outcome measure to the Swiss men who have sex with men (MSM) population (estimated size of the population of MSM between 15 and 64 years old: 64 000–96 000 men²⁰).

§Of 402 (58.4%) respondents who heard of the campaign 95 MSM with HIV risk (MSMwr) respondents indicated that they adopted an HIV risk reduction strategy in April and maintained it until HIV testing in May (95/688=13.8%).

¶Of 402 (58.4%) respondents who heard of the campaign 19 MSMwr respondents indicated that they adopted their risk behaviour in order to comply with the key message of the campaign (19/688=2.8%).