Intervene before leaving: clustered lot quality assurance sampling to monitor vaccination coverage at health district level before the end of a yellow fever and measles vaccination campaign in Sierra Leone in 2009

Table 4 Results of the clustered lot quality assurance sampling surveys ^* to monitor yellow fever vaccination coverage before the end of the campaign, Sierra Leone, 28–29 November 2009

District	Lot	N	Vaccination Card^§			Verbal History
District	Lot	N	U	D	SE	U	D	SE
Western Area Rural	1	50	2	A	0.02	1	A	0.02
Western Area Urban	2	50	4	A	0.05	4	A	0.05
Kambia	3	50	0	A	0.00	0	A	0.00
	4	50	0	A	0.00	0	A	0.00
	District Total	100	0	A	0-00	0	A	0.00
Koinadugu	5	50	6	A	0.06	4	A	0.05
	6	50	10	R	0.07	8	R	0.08
	District Total	100	16	R	0.05	12	A	0.05
Port Loko	7	50	18	R	0.19	14	R	0.17
	8	50	7	A	0.12	7	A	0.12
	9	50	11	R	0.09	7	A	0.04
	District Total	150	36	R	0.08	28	R	0.07
Tonkolili	10	50	2	A	0.02	1	A	0.02
	11	50	2	A	0.02	2	A	0.02
	12	50	1	A	0.02	0	A	0.00
	District Total	100	5	A	0.01	3	A	0.01

N: sample size; U: number of Unvaccinated in the sample; D: Decision; A: Accepted; R: Rejected; SE: Standard Error of the distribution of the vaccination variable between the clusters in the lots.
* Sampling plans used: UT = 90% and LT = 75%, with d = 7 when N = 50 (5x10); d = 15 when N = 100 (10x10); d = 25 when N = 150 (15x10).
§ Used to take operational decisions in the field before the end of the campaign.

ISSN: 1471-2458