Primary health-care services are a major element of any health-care system (Raposo et al., 2009), as it brings health care closer to citizens’ place of residence and work, operating as their first level of contact with health-care system (Cueto, 2004). Public primary health-care services in Greece are delivered through a dual system of primary health-care centres, and hospital outpatient services, which are part of the National Healthcare System and Social Insurance Organization (Papanikolaou and Zygiaris, 2014; Fotiadis and Vassiliadis, 2013). Despite the efforts that have been undertaken over the past decade to modernize and improve the national health-care services (Papanikolaou and Ntani, 2008), its structural and functional efficiency needs to be further improved by upgrading the quality of the relevant services offered (Oikonomou et al., 2015). The ongoing recession puts even more to find ways to balance out the deteriorating government spending on public health system via an effective mechanism that will improve these services. This becomes even more important as the vast majority of individuals, due to tight economic conditions, report to the public system first, leaving the private as the last resort. For the state and health-care organizations to plan and deliver better primary health-care services, it is fundamental to identify and assess which service factors should be improved to meet some high standards and gain positive behavioral responses (Raposo et al., 2009; Meesala and Paul, 2016). Our intention is to go beyond the study of individual factors and their effect on the health-care system by measuring the quality of the delivered primary health-care services from hospital outpatient departments and especially the customeroriented quality assessment measures where several behavioral responses are rooted (Dagger et al., 2007; Oikonomou et al., 2015). Despite the fact that primary health-care services are a vital substance for a wellfunctioning society, there are only a few reliable and valid instruments to effectively measure service quality and tackle the complexities of the primary health-care service setting. Previous service quality conceptualization efforts usually use multidimensional models to assess service quality in the health-care context (Otani and Kurz, 2003; Dagger et al., 2007; Raposo et al., 2009; Sumaedi et al., 2016; Miranda et al., 2012; Shabbir et al., 2016). Based on the fact that customers tend to judge their experience as a whole rather than evaluating each single sub-process separately (Sousa and Voss, 2012), many studies consider service quality as a multidimensional reflectively measured higher-order construct (Sumaedi et al., 2016; Hossain et al., 2015). However, existing literature argues that the formative measurement approach with composite indicators might be more appropriate to uncover the formation of service quality perception (Collier and Bienstock, 2006; Carlson and O’Cass, 2011; Sousa and Voss, 2012).