Modelling the cost-effectiveness of a newborn hearing screening programme; usability and pitfalls

Figures & data

Figure 1. Structure of the web tool.

Table 1. Referral rates and specificities per screening step in well baby NHS of several European and other countries.

		Referral rates (%)				Specificities (%)
		st 1	st 2	st 3	st 4	st 1	st 2	st 3	st 4
Austria	OAE-OAE	6	51			94	50
Belgium Fl	aABR-aABR	4	40			96	62
Belgium W	OAE-OAE	15	24			85	77
Cyprus	OAE-OAE-aABR	4	15	n.a.		96	88
Greece	OAE-OAE-aABR	13	30	n.a.		87	71
Ireland	OAE-OAE-aABR	6	50	n.a.		94	51
Israel	OAE-aABR	4	55			96	46
Netherlands	OAE-OAE-aABR	4	34	18		96	68	90
Slovenia	OAE-OAE	2	31			98	73
Spain As	OAE-OAE-OAE	8	23	61		92	78	42
Sweden St	OAE-OAE-OAE-aABR	4	31	73	60	96	71	29	46

The available referral rates with high validity (EUSCREEN inventory data) were converted to specificities, using values of prevalence 1.2/1000, attendance 100% and sensitivity 99%. Referral rates of step 3 from Cyprus, Greece and Ireland were not available.

(Fl: Flanders; W: Wallonia; As: Asturias; St: Stockholm; st: screening step; n.a.: not available).

Table 2. Modelling an Albanian NHS programme.

	OAE-OAE-aABR	OAE-OAE	OAE-aABR	aABR-aABR
Input
Population screened 10,000 HI prevalence 1.2/1000
Timing screening steps (days)	2, 15, 22	2, 15	2, 15	2, 15
Attendances (%)	97, 66, 60	97, 66	97, 66	97, 66
Sensitivity all steps (%)	99	99	99	99
Referral rates (%)	7, 14, 42	7, 14	7, 5	7, 5
Devices needed OAE / aABR	30 / 5	30	25 / 5	30
Outcome
Number of tests	10,186	10,148	10,148	10,148
Number of referrals to DA	16	63	22	22
HI cases detected (of 12)	4	8	8	8
Costs of screening (€)	167,922	155,805	162,252	235,208
Costs of DA (€)	553	2,196	784	784
Costs of screening and DA (€)	168,475	158,001	163,036	235,992
Costs per case detected (€)	37,690	20,627	21,284	30,808

Attendance diagnostic assessment: 70%. Costs: devices OAE €6,500, aABR €10,000, salary screener €3/hr, diagnostic assessment €50. (DA: diagnostic assessment).

Table 3. Three NHS protocols with different numbers of steps analysed by the web tool, and two alternatives for the OAE-OAE-OAE-aABR protocol.

	aABR- aABR	OAE-OAE-aABR	OAE-OAE- OAE-aABR	OAE- OAE- OAE	OAE- OAE-aABR
Input
Population 10,000 HI prevalence 1.2/1000
Timing screening steps (days)	10, 12	6, 18, 30	2, 18, 25, 25	2, 18, 25	2, 18, 25
Attendances all steps (%)	99	99	99	99	99
Sensitivity all steps (%)	99	99	99	99	99
Referral rates (%)	4, 40	4, 34, 18	4, 31, 73, 60	4, 31, 73	4, 31, 25
Devices needed OAE / aABR	25	25 / 5	30 / 5	30	25 / 5
Outcome
Number of tests	10,292	10,424	10,499	10,412	10,412
Number of referrals to DA	157	24	52	88	30
HI cases detected (of 12)	12	11	11	11	11
Costs of screening (€)	268,616	190,671	197,673	195,889	196,712
Costs of DA (€)	77,624	11,758	25,825	43,477	14,889
Costs of screening + DA (€)	346,240	202,429	223,498	239,366	211,601
Costs per case detected (€)	29,618	17,695	19,973	20,924	18,497

The input of these alternatives is the same as for the OAE-OAE-OAE-aABR protocol, except for the third screening step of the OAE-OAE-aABR protocol, for which a referral rate of 25% is entered.

Attendance diagnostic assessment: 99%. Costs: devices OAE €6,000, aABR €10,000, salaries €15/hr, diagnostic assessment €500. (DA: diagnostic assessment).

Table 4. Maternity or screening after discharge with low and high attendances.

OAE-OAE-aABR	Maternity	Health centre low attendance	Home visit high attendance
Input
Population screened 10,000 HI prevalence 1.2/1000
Timing screening steps (days)	2, 3, 28	6, 14, 35	6, 14, 35
Attendances (%)	99, 99, 95	95, 95, 95	99, 99, 95
Sensitivity all steps (%)	99	99	99
Specificity per step (%)	86, 50, 90	95, 70, 90	95, 70, 90
Devices needed OAE / aABR	25 / 5	25 / 5	25 / 5
Outcome
Number of tests	11,944	10,100	10,552
Number of referrals to DA	76	23	25
HI cases detected (of 12)	11	10	11
Costs of screening (€)	214,361	185,564	191,821
Costs of DA (€)	36,071	10,843	11,776
Costs of screening and DA (€)	250,433	196,408	203,597
Costs per case detected (€)	22,767	19,759	18,509

Attendance diagnostics: 95%. Costs: devices OAE €6,000, aABR €10,000, salaries €15/hr, diagnostic assessment €500. (DA: diagnostic assessment).

Table A1. Validation of the model using Dutch NHS data.

	Data Dutch NHS programme 2019		OOA model predictions
	OOA	all infants	input	outcome
N infants screened	165,520	165,708	165,708
N tests steps 1 + 2 + 3	174,836			174,524
Refers (%) step 1	4.4		4
Refers (%) step 2	32.7		33
Refers (%) step 3	21.4		21
Sensitivity (%) all steps	unknown		99
Attendance (%) step 1	99.6		100
Attendance (%) step 2	99.6		100
Attendance (%) step 3	99.6		100
N refers to DA	488	606		459
Attendance (%) DA		92.7	93
N detected HI		206		228
Prevalence HI (x/1000)			1.4
P x N infants screened			232
% HI infants detected			98.7

NHS: Neonatal Hearing Screening; O: otoacoustic emissions A: automated auditory brainstem response; N: number; DA: diagnostic assessment; HI: hearing impairment; P: prevalence.

Table A2. Guidance mode.

Sensitivity: all screening steps
programme quality		low / medium		high
sensitivity (%)		95		99
Specificity screening step 1
age (days)	0	1	2	3	4 or more
OAE specificity (%)	65	71	86	92	94
aABR specificity (%)	73	79	90	93	94
programme quality			low	medium	high
specificity reduced by			10	5	0
Specificity subsequent screening steps
interval between steps (days)			0	1-7	>7
specificity (%)			30	50	60

Values of sensitivity determined by the quality of the screening programme; specificity values of screening step 1 determined by age, the type of test and quality (a reduction for low and medium quality), and specificity values of subsequent steps, determined by the duration of the interval since the previous step.