Phase‐specific networks of job stress, anxiety and insomnia during acute crisis and chronic strain: A citywide study of public health nurses in Shanghai

ABSTRACT Background Psychological distress among public health nurses (PHNs) during major public health emergencies may vary across response phases, from acute crisis to prolonged chronic strain. Although the mental health consequences of sustained emergency response are well documented, evidence on how symptom connectivity patterns differ across acute and chronic phases remains limited. Aims This study aims to compare symptom centrality and connectivity patterns of job stress, anxiety and insomnia among PHNs during acute crisis and chronic strain and to identify phase‐specific associations that may inform tailored intervention strategies. Methods We conducted a city‐wide, two‐wave census survey of PHNs across all 249 community health centres in Shanghai, China. Data were collected during the acute crisis phase (October–November 2022; n = 1565) and the chronic strain phase (November 2023–January 2024; n = 1718), with response rates exceeding 96% at both waves. Validated instruments were used to assess job stress, anxiety and insomnia. Undirected symptom networks were estimated using graphical least absolute shrinkage and selection operator models to characterise symptom connectivity patterns, whereas Bayesian network modelling was used to explore conditional probabilistic dependencies among symptoms. Exploratory subgroup analyses examined network heterogeneity by age and working hours. Results Overall psychological distress was lower during the chronic strain phase than during the acute crisis phase; however, symptom‐level connectivity patterns differed between the two phases, with notable differences in centrality. Conflicting responsibilities and limited opportunity to draw on prior experience and training showed stable metric‐specific centrality across both phases. During the acute phase, network centrality was anchored by operational instability—including unclear roles and high effort demands—alongside anxiety‐related hyperarousal. During chronic strain, the most central nodes were characterised by sustained workload burden and impaired recovery, such as difficulty relaxing. Bayesian models consistently positioned work‐related stressors at upstream positions within the distress architecture. Subgroup analyses revealed that symptoms were more tightly interconnected among younger PHNs (< 36 years) during acute crisis. Conclusions The psychological architecture of workforce distress is phase‐specific; therefore, ‘one‐size‐fits‐all’ interventions are inadequate. Interventions should prioritise operational clarity during acute crises and workload management and recovery support during prolonged strain. Integrating these phase‐adapted strategies into public health systems may help sustain a resilient frontline workforce.