Table 1.

ELSA achieved sample numbers^a and response rates^b

	1	2	3	4	5
Wave	2002–03	2004–05	2006–07	2008–09	2010–11
Wave 1 sample, number interviewed	11 391	8780	7536	6623	6242
Wave 3 refreshment sample, number interviewed	n/a	n/a	1275	972	936
Wave 4 refreshment sample, number interviewed	n/a	n/a	n/a	2290	1912
Wave 1 sample members interviewed who participated in all preceding waves	11 391	8780	7198	6019	5316
Wave 1 sample members who have died (cumulative)	n/a	504	1164	1620	2158
Wave 1 sample members field response rates (based on issued cases)b	67%	82%	73%	74%	78%

^aBased on core members only. The totals for productive interviews include those in care homes/institutions.

^bThose in care homes/institutions are excluded from the response rate calculations.