Detection of antibiotic resistance is essential for gonorrhoea point-of-care testing: a mathematical modelling study

Table 1 Gonorrhoea testing and treatment parameters and their default values

Parameter	Description (unit)	Baseline	Culture	NAAT	POC+R	POC−R
τ _S	Rate at which symptomatic individuals seek care (y⁻¹)	Variable ^a	See baseline	See baseline	See baseline	See baseline
τ _A	Rate at which asymptomatic individuals seek care (y⁻¹)	Variable ^a	See baseline	See baseline	See baseline	See baseline
ξ _G	Test sensitivity to detect gonorrhoea	99% ^b	See baseline	See baseline	See baseline	See baseline
ξ _R	Test sensitivity to detect resistance against the first-line antibiotic	Any value	99% ^c	0% ^d	99% ^c	0% ^d
η ₁, η ₂	Efficacy of first-line (1) or second-line (2) antibiotic	99% ^e	See baseline	See baseline	See baseline	See baseline
δ	Average time after test individuals return for treatment (days)	7 ^f	See baseline	See baseline	0 ^d	0 ^d
1/ω	Average time individuals with resistant gonorrhoea wait for re-treatment (days)	7 ^c	See baseline	See baseline	See baseline	See baseline
λ _A	Fraction of asymptomatic individuals who return for treatment	90% ^c	See baseline	See baseline	100% ^d	100% ^d
λ _S	Fraction of symptomatic individuals who remain symptomatic after failed treatment	90% ^c	See baseline	See baseline	See baseline	See baseline
ψ	Fraction of successfully treated individuals who were symptomatic at baseline	60% ^f	–	–	–	–

Unless a value is set by definition, all values listed are default values and are varied in sensitivity analyses. Baseline: Resistance-free scenario (corresponds to scenario where culture or NAAT is used; ξ _R can take any value since there is no resistance to detect). Culture, NAAT, POC−R, or POC+R refer to scenarios after resistance is introduced
NAAT nucleic acid amplification test, POC point-of-care, POC+R POC test with resistance detection, POC−R POC test without resistance detection
^aDerived
^b[35]
^cAssumption
^dBy definition
^e[23, 36]
^f[11]