No abstract

Summary Incidence data of childhood leukaemia (CL) in Hong Kong (1 984-90) have been analysed for evidence of variation between small areas. All cases (n=261) were classified by morphological cell type, with the majority (n=205) being acute lymphoblastic leukaemia (ALL), and haematological review has permitted immunophenotypic classification for 73% of these. The data have been examined for evidence of spatial clustering within small census areas (TPUs) and for association with population mixing, with attention focused on those subgroups (especially the childhood peak of ALL -taken here to be diagnoses in children from 24 months up to the seventh birthday -and common ALL) which, it has been hypothesized, may be caused by unusual patterns of exposure and response to common infections. For the whole of Hong Kong, there was evidence of spatial clustering of ALL at ages 0-4 years (P = 0.09) and in the childhood peak (P<0.05). When these analyses were restricted to TPUs where extreme population mixing may have occurred, overall incidence was elevated and significant evidence of clustering was found for ALL (P<0.007) at these ages and for the common ALL in the childhood peak (P= 0.032). Replication of the analyses for subsets of leukaemia that were not dominated by the childhood peak of ALL found no evidence of clustering. This is the first investigation of an association between population mixing and childhood leukaemia in Asia and the first to include clustering and to consider particular subsets. The results are supportive of the 'infectious' aetiology hypothesis for subsets of childhood leukaemia, specifically common ALL in the childhood peak.

In this cross-sectional study, we compared the quality of life (QOL) in transfusion-dependent thalassemic patients who survived matched sibling hematopoietic SCT (HSCT, n ¼ 24) with patients treated conventionally with transfusion and iron chelation (n ¼ 74). WHOQOL-BREF(HK) and PedsQL questionnaires were administered to patients aged 418 years and 5-12 years, respectively. Patients aged 12-18 years received both questionnaires. WHOQOL-BREF(HK) revealed post transplant patients rated overall health better than those treated conventionally (score 3.67 vs 3.06, P ¼ 0.01). They are less dependent on medical aids (3.87 vs 2.96, P ¼ 0.006), having higher activity level (4.00 vs 3.36, P ¼ 0.026) and better personal relationships (4.13 vs 3.69, P ¼ 0.014). Physical health domain score was better (75.20 vs 63.94, P ¼ 0.007). These differences remained significant after adjustment for comorbidities. PedsQL revealed post transplant patients rated better for running (3.53 vs 2.72, P ¼ 0.001) and sports (3.20 vs 2.64, P ¼ 0.038), even after adjustment for comorbidities, but were less satisfied for school absence to attend hospital (2.53 vs 3.29, P ¼ 0.03). Post transplant patients were significantly more likely to consider marriage (100 vs 75.7%, P ¼ 0.033), but not childbearing (66.7 vs 51.4%, P ¼ 0.28). In conclusion, transplanted thalassemic patients enjoy better QOL, mainly in physical health, compared with conventionally treated patients. This information is important to patients considering HSCT.