Table 1.

Probabilities, costs, and utilities used in the model.

Variable	Value	Range considered in sensitivity analysis	Reference
Sensitivity of cfDNA for microdeletion syndromes 22q11.2, PWA, 1p36 and Cri-du-chat.	0.986	0.1–1	[1,24]
Specificity of cfDNA microdeletions	0.991	0.1–1	[1,24]
Population prevalence of 22q11.2	0.000168	0.0001–0.001	[19]
Population prevalence of PWA	0.0000378	0.00001–0.0001	[21,23]
Population prevalence of 1p36	0.0001	0.00001–0.001	[22]
Population prevalence of Cri-du-chat	0.0000728	0.00001–0.0001	[20]
Probability of amniocentesis uptake	0.7	0.1–1.0	[27]
Probability of amniocentesis-related loss	0.006	0.001–0.01	[28]
Probability of abnormal US in 22q11.2	0.868	0.6–0.95	[6]
Probability of abnormal US in PWA	0.273	0.1–0.5	[7]
Probability of abnormal US in 1p36	0.279	0.1 −0.5	[25,26]
Probability of abnormal US in Cri-du-chat	0.482	0.2–0.7	[9]
Termination rate in 22q11.2	0.689	0.3–1.0	[6]
Termination rate in PWA	0.812	0.3–1.0	[29]
Termination rate in 1p36	0.836	0.3–1.0	[32]
Termination rate in Cri-du-chat	0.836	0.3–1.0	[32]
Probability of fetal loss in 22q11.2	0.361	0.1–0.5	[31]
Probability of fetal loss in PWA	0.361	0.1–0.5	[31]
Probability of fetal loss in 1p36	0.64	0.5–0.85	[31]
Probability of fetal loss in Cri-du-chat	0.64	0.5–0.85	[31]
Probability of normal fetal loss	0.005	0.001–0.01	[41]
Probability of neonatal death in 22q11.2	0.164	0.01–0.3	[6]
Probability of neonatal death in PWA	0.164	0.1–0.4	[6]
Probability of neonatal death in 1p36	0.7	0.5–0.9	[30]
Probability of neonatal death in Cri-du-chat	0.7	0.3–0.9	[30]
Probability of neonatal death in normal fetus	0.00218	0.001–0.005	[42]
Cost of cfDNA screen for aneuploidies	$1,726	$0–10,000	[33]
Cost of cfDNA screen for aneuploidies with added microdeletions	$0	$0–5,000	See text
Cost of genetic counseling	$95	$50–150	[27]
Cost of 20-week ultrasound	$229	$100–500	[34]
Cost of amniocentesis	$584	$400–1,000	[27,36]
Cost of postnatal diagnosis	$282	$100–700	[36]
Cost of termination or fetal loss	$3,165	$2,500–4,000	[27]
Cost of neonatal death	$111,940	$90,000–115,000	[35]
Cost of lifetime 22q11.2	$1,249,429	$900,000–1,500,000	See text
Cost of lifetime PWA	$1,252,029	$900,000–1,500,000	See text
Cost of lifetime 1p36	$1,252,029	$900,000–1,500,000	See text
Cost of lifetime Cri-du-chat	$1,295,654	$900,000–1,500,000	See text
Cost of first 2 years of DS	$89,799		See text
Cost of lifetime DS	$1,072,352		[27]
Utility of amniocentesis-related or spontaneous fetal loss during 2nd/3rd trimester	0.93	0.9–0.95	[38]
Utility of pregnancy termination	0.91	0.85–0.95	[38]
Utility of neonatal death	0.76	0.7–0.8	[39]
Utility of neonate with 22q11.2	0.81	0.75–0.86	[38]
Utility of neonate with PWA	0.81	0.75–0.86	[38]
Utility of neonate with 1p36	0.65	0.6–0.7	[39]
Utility of neonate with Cri-du-chat	0.65	0.6–0.7	[39]
Utility of normal neonate	1	Assumed	[38]

PWA: Prader–Willi and Angelman syndromes; US: ultrasound; DS: Down syndrome.