Table 1.

Monitoring of quality indicators for blood cultures for 2019

		No. of bottles				Delay (mean)			No. of positives	Virtuo false-positivity rate
		Total	FA	FN	PF	Reception	Loading in Virtuo	Unloading in Virtuo		No. of false positives*	No. of false positives*/ total (%)	No. of false positives*/ total positives (%)	Measured bottles (FN, FA)	Low volumes <7 ml	High volumes >13 ml	Conforming volumes† (among measured)	Non-conforming volumes† (among measured)	Conforming volumes † (total)	Non-conforming volumes † (total)
January	n	1436	688	686	62	4.3 h	40 min	7.35 h	148	0			625	419	35	171	454	171	454
	%		48	48	4				10		0	0	44	29	2	27	73	12	32
February	n	5159	2485	2475	199	3.7 h	43 min	5.5 h	524	2			3277	2117	280	880	2397	880	2397
	%		48	48	4				10		0.04	0.38	64	41	5	27	73	17	46
March	n	5300	2528	2529	243	3.3 h	45 min	5.8 h	576	3			3367	2212	246	909	2458	909	2458
	%		47.5	47.5	5				11		0.06	0.52	64	42	5	27	73	17	46
April	n	5009	2390	2388	231	3.6 h	49 min	5.8 h	538	4			3006	2007	244	755	2251	755	2251
	%		47.5	47.5	5				11		0.08	0.74	60	40	5	25	75	15	45
May	n	4827	2310	2307	210	3.9 h	47 min	6.0 h	432	3			2827	1759	284	784	2043	784	2043
	%		48	48	4				9		0.06	0.69	59	36	6	28	72	16	42
June	n	4843	2304	2299	240	3.9 h	47 min	5.3 h	542	2			2891	1631	317	943	1948	943	1948
	%		47.5	47.5	5				11		0.04	0.37	60	34	7	33	67	19	40
July	n	4739	2270	2270	199	3.1 h	39 min	5.8 h	556	0			2426	1494	210	722	1704	722	1704
	%		48	48	4				12		0.00	0.00	51	32	4	30	70	15	36
August	n	3881	1827	1820	234	2.7 h	37 min	5.8 h	474	0			2223	1351	190	682	1541	682	1541
	%		47	47	6				12		0.00	0.00	57	35	5	31	69	18	40
September	n	4367	2067	2071	229	3.1 h	44 min	4.2 h	457	5			2727	1669	270	788	1939	788	1939
	%		47.5	47.5	5				10		0.11	1.09	62	38	6	29	71	18	44
October	n	4926	2327	2326	273	3.6 h	43 min	6.0 h	528	9			3416	2096	354	966	2450	966	2450
	%		47	47	6				11		0.18	1.70	69	43	7	28	72	20	50
November	n	4837	2288	2289	260	3.8 h	48 min	6.3 h	493	2			3321	1991	354	976	2345	976	2345
	%		47.5	47.5	5				10		0.04	0.41	69	41	7	29	71	20	48
December	n	4568	2144	2144	280	3.6 h	44 min	6.4 h	504	5			2954	1760	337	857	2097	857	2097
	%		47	47	6				11		0.11	0.99	65	39	7	29	71	19	46
Total	n	53 892	25 628	25 604	2660	3.5 h	44 min	5.8 h	5772	35			33 060	20 506	3121	9433	23 627	9433	23 627
	%		47.5	47.5	5				11		0.07	0.61	60	37	6	30	70	17	43

∗ False positive, bottles with positive signal with BacT/Alert Virtuo and negative culture.

†Conforming volumes, volumes between 7 and 13 ml.

nd:,not determined; FA, aerobic bottles; FN, anaerobic bottles; PF, paediatric bottles.