摘要：Objectives. We examined the coevolution of information sharing and implementation of evidence-based practices among US and Canadian tobacco cessation quitlines within the North American Quitline Consortium (NAQC). Methods. Web-based surveys were used to collect data from key respondents representing each of 74 participating funders of NAQC quitlines during the summer and fall of 2009, 2010, and 2011. We used stochastic actor-based models to estimate changes in information sharing and practice implementation in the NAQC network. Results. Funders were more likely to share information within their own country and with funders that contracted with the same service provider. Funders contracting with larger service providers shared less information but implemented significantly more practices. Funders connected to larger numbers of tobacco control researchers more often received information from other funders. Intensity of ties to the NAQC network administrative organization did not influence funders’ decisions to share information or implement practices. Conclusions. Our findings show the importance of monitoring the NAQC network over time. We recommend increased cross-border information sharing and sharing of information between funders contracting with different and smaller service providers. Tobacco use is still the leading cause of preventable death in Canada and the United States. Although smoking among adults has been declining, currently 16% of Canadian adults and 19% of American adults are smokers. 1,2 Many smokers trying to quit fail, and those who succeed often have attempted to quit multiple times. 3,4 A number of governments, including that of Canada, have required tobacco companies to include warning labels with toll-free numbers for tobacco cessation quitlines, and many, including the US government, have launched mass media campaigns promoting these toll-free numbers. In North America, a quitline is a partnership between 2 or more organizations (composed of 1 or 2 funders and a provider organization) in which telephone-based tobacco cessation services are provided to people trying to quit smoking. The funder is typically the department of public health in each US state or a similar government agency in Canada. Funders determine the services to be offered while contracting out responsibility for actual service provision to public, nonprofit, or for-profit providers. In the United States and Canada, 65 quitlines now operate independently and provide various cessation services. Even though substantial evidence is available regarding the specific cessation practices that are effective, not all quitlines implement the same practices. 5 However, all quitlines have the same goal (helping smokers quit) and share information and resources regarding tobacco cessation services under the umbrella of the North American Quitline Consortium (NAQC). A network administrative organization (NAO) 6 facilitates the coordination and governance of the NAQC network and offers professional support, educational programs, and activities designed to help improve quitlines. 7 We examined the evolution of information sharing and implementation of evidence-based practices in this network; our specific focus was on funders given that they ultimately determine the services to be offered by their quitline. Figure 1 shows all of the NAQC organizations and the service delivery information ties reported by funders in 2009. Open in a separate window FIGURE 1— Service delivery information received and reported by funder organizations in 2009: North American Quitline Consortium. Note . F = funder; NAO = network administrative organization; P = service provider; QL = quitline. aNonrespondent. Networks have been found to play an important role in the dissemination and provision of evidence-based practices in health and human services. 8–12 Organizations often depend on information from others for determining the practices that are most effective, 5,13–15 and teasing out which sources influence service delivery is important for public health networks aiming to disseminate information to improve service delivery. Knowing the factors that condition the selection of information sources and which of these sources influence the implementation of evidence-based practices will increase our understanding of the dynamics underlying dissemination of practices within networks. Previous studies showed that awareness of evidence-based practices was highest among NAQC funders that were strongly connected to researchers and that greater network centralization through the consortium’s NAO was associated with higher adoption rates. 5,11 However, these studies did not focus on implementation of evidence-based practices and were unable to draw causal conclusions. Information sharing among funders and implementation of services may be influenced by the local network in which a funder is embedded. Funders may depend on other funders, providers, the NAO, and researchers to receive information regarding the efficacy, reach, and delivery of tobacco cessation services, and by doing so they potentially increase the effectiveness of their quitlines. Along the lines of a homophily argument, funder-to-funder ties may be most informative and influential. However, diversity of information sources might lessen the dependence on funder ties. 16 If a funder is strongly connected to the NAO, service providers, or researchers, implementation of evidence-based practices may increase but connections to other funders may become redundant. Factors such as funder country, quitline age, and provider size may also play a role in network and implementation dynamics. Network ties are often bounded by geospatial conditions, 17,18 and US and Canadian quitlines show a tendency to share information within their own country. 7 Older quitlines may be more active or successful in establishing and maintaining network links, 19 consistent with an accumulative advantage argument. 16 Furthermore, because a provider may have contractual ties with funders of multiple quitlines, it can be expected that a funder contracting with such a provider will learn from the other funders working with that provider, which may influence implementation of practices. Our goals were to develop a network analysis model of public health service delivery and to provide insight into the functioning of tobacco quitlines as a specific case study. We used stochastic actor-based models 20 to simultaneously examine the evolution of information sharing among funders and implementation of evidence-based practices by funders’ quitlines. These advanced network models can represent an extensive assortment of influences on network change, allow estimation of parameters expressing these influences, and provide tests of corresponding hypotheses. 21 Such models have been used successfully in a number of studies to examine the evolution of various organizational networks. 19,22–25 However, none of these investigations focused on information sharing and simultaneously modeled the evolution of an outcome. Our study can serve as an example of the ways in which public health services in the United States and Canada are organized, with governments contracting for health services with providers or engaging with the research community to address public health issues. Our 2 primary research questions were as follows: Which network ties and funder characteristics influence information sharing among funders? and Which network ties and funder characteristics influence implementation of evidence-based practices?
