Socioeconomic differences in primary healthcare use before childhood cancer diagnosis: a register-based cohort study in Sweden.

BACKGROUND: Early diagnosis of childhood cancer remains challenging because initial symptoms are common, nonspecific and have low predictive value in primary healthcare (PHC). We assessed whether socioeconomic differences shape pre-diagnostic PHC pathways before childhood cancer diagnosis. METHODS: We conducted a register-based matched cohort study using PHC data from three Swedish regions between 2001 and 2022, covering 54% of the general paediatric population in Sweden. Children aged 0-19 years with a first cancer diagnosis were matched 1:25 to cancer-free population references by age, sex and region. In-person PHC physician contacts in the year before the index date were analysed. Logistic and negative binomial regression models were used to assess socioeconomic differences in PHC utilisation and PHC contact frequency, respectively stratified by diagnostic group. RESULTS: The study included 3711 childhood cancer patients and 93 181 references. Children with cancer had more PHC contacts than population references in the year before diagnosis (mean 2.28 vs 1.27, mean difference 1.01, 95% CI 0.94 to 1.08; p<0.001), although 22%-49% had no PHC contact 3 months before diagnosis depending on diagnostic group. Maternal educational gradients in PHC use were present in the general paediatric population but largely absent among children with cancer. An exception was central nervous system (CNS) tumours, for which children of mothers with low educational attainment had 28% more prediagnostic PHC contacts than those with highly educated mothers. CONCLUSION: Socioeconomic differences in PHC utilisation by maternal educational level largely diminish as children approach a cancer diagnosis, except for CNS tumours, where increased contacts among children of mothers with low educational attainment may indicate a prolonged or delayed diagnosis.