Timing of progression from Chlamydia trachomatis infection to pelvic inflammatory disease: a mathematical modelling study

Table 2 Estimated fraction progressing from chlamydia infection to PID, using baseline values

Progression to PID	Fraction progressing, % (95% CI)^*	Cumulative incidence of PID after one year, % (95% CI)^†		Akaike’s Information Criterion^‡
Progression to PID	Fraction progressing, % (95% CI)^*	Control group	Intervention group	Akaike’s Information Criterion^‡
Data
Results from RCT		1.9 (1.2 to 2.9)	1.3 (0.7 to 2.1)
Model
Immediate progression	8.3 (5.7 to 11.0)	1.6 (1.1 to 2.1)	1.6 (1.1 to 2.1)	13.3
Constant progression	9.9 (6.8 to 13.0)	1.7 (1.2 to 2.3)	1.5 (1.0 to 1.9)	12.1
Progression at the end	10.0 (6.8 to 13.1)	1.7 (1.2 to 2.3)	1.5 (1.0 to 1.9)	12.1

^*The 95% CI is obtained by using the corresponding standard error and assuming a normal distribution.
^†Cumulative incidence of PID after one year caused by chlamydia and other microorganisms together.
^‡ Akaike’s information criterion values describe fit of model.
PID, pelvic inflammatory disease; RCT, randomised controlled trial; CI, confidence interval.

ISSN: 1471-2334