Statistical Analysis
All patients follow-up was done by outpatient service and telephone. All
patients without outpatient follow-up records within 6 months were
confirmed by telephone follow-up. Follow-up was updated as of 30th
September, 2020.Complete blood counts, Hb composition analysis,
transfusion volume were compared before and after treatment. Chi square
tests were used to calculate comparisons between groups. Data were shown
as mean (95% confidence interval) or median (range).Changes in HbF
level were compared using Kruskal-Wallis H test between different groups
of treatment response. One-way ANOVA analysis of variance or
Kruskal-Wallis H test was performed to determine factors that predicted
efficacy, including start dosage of thalidomide, thalidomide dosage
after third month visit and age. Cochran-Mantel-Haenszel Chi-square test
was performed to compare the distribution of variants of sex, genotype
category, transfusion interval before thalidomide treatment, whether Hb
decreased during the first month of treatment between different groups
of treatment response.To evaluate the performance of independent risk
factors in predicting major responders, the receiver-operating
characteristic (ROC) curve analysis was performed and the optimal
cut-off values were obtained from the Youden’s index. Diagnostic
accuracy was expressed as the sensitivity, specificity, positive
predictive value, negative predictive value, and the area under the ROC
curve (AUC).Statistical analysis was performed by using SPSS 22.0 (SPSS
Institute, Cary, NC). P values <0.05 were considered
significant.