Table 3

Positive sputum cultures as a percentage of notifications

		Years
		1981-3	1984-6	1987-8	1989-92	1993-96
Total ISC notifications	237	128	85	179	163
Positive sputum cultures	32	23	11	41	39
As % of total	13.5	18.0	12.9	22.9	23.9
χ²with continuity correction
1981–3	—
1984–6	0.97	—
1987–8	0.00	0.62	—
1989–92	5.60^*	0.82	3.01	—
1993–6	6.49^*	1.18	3.53	0.01	—
Mantel-Haenszel test of linear association		8.72^**
Total white notifications	129	88	38	57	34
Positive sputum cultures	49	34	18	29	17
As % of total	38	38.6	47.4	50.9	50
χ² with continuity correction
1981–3	—
1984–6	0.00	—
1987–8	0.72	0.51	—
1989–92	2.20	1.64	0.02	—
1993–6	1.15	0.88	0.00	0.00	—
Mantel-Haenszel test of linear association		3.86^*