2.3.2. Constructing and comparing PSR-networks

Based on clinicians’ PSR, one network per clinician was constructed (four in total). Clinicians’ indications on the strength of the relation between a symptom pair were used as edges weights (‘do not relate’ = 0, ‘relate weakly positive/negative’ = (−)0.2, ‘relate positive/negative’ = (−)0.5, ‘relate strongly positive/negative’ = (−)0.7, ‘relate very strongly positive/negative’ = (−)1). Through averaging edge weights for each symptom pair an average PSR-network was created. Strength and expected influence of each symptom were investigated for all PSR-networks. To assess the similarity of the individual PSR-networks, the edge weights and centrality indices (strength and expected influence) of all PSR-networks were correlated with each other. Further, to inspect the similarity of the general structure of these networks, we assessed the number of edges on which the individual PSR-networks agreed regarding the presence or absence of the edge.