Table 2 Contribution of the three different effects to the differences in life expectancy at birth by age and time period; Spain 1987–2001

Period	Effect	Males
		0–24		25–49		50–84		⩾85		Total
		N	%	N	%	N	%	N	%	N	%
1987–91 to 1992–6	Direct effect	0.0114	3.10	−0.0113	5.90	0.1124	19.09	0.0286	100	0.1411	17.80
	Indirect effect	0.3527	96.03	−0.1776	92.74	0.4605	78.24	–	–	0.6356	80.17
	Interaction	0.0029	0.79	−0.0026	1.36	0.0158	2.68	–	–	0.0161	2.03
	Total	0.3673	100	−0.1916	100	0.5885	100	0.0286	100	0.7928	100
1992–96 to 1997–2001	Direct effect	0.0076	2.66	0.0347	5.96	0.1441	18.25	−0.0053	100	0.1811	10.96
	Indirect effect	0.2722	95.11	0.5334	91.59	0.6258	79.26	–	–	1.4314	86.60
	Interaction	0.0062	2.17	0.0143	2.45	0.0198	2.50	–	–	0.0403	2.44
	Total	0.2862	100	0.5824	100	0.7895	100	−0.0053	100	1.6528	100

Period	Effect	Females
		0–24		25–49		50–84		⩾85		Total
		N	%	N	%	N	%	N	%	N	%
1987–91 to 1992–6	Direct effect	0.0048	2.20	0.0000	0.00	0.1470	18.32	0.1264	100	0.2782	24.45
	Indirect effect	0.2103	96.51	−0.0089	101.14	0.6254	77.93	–	–	0.8268	72.65
	Interaction	0.0029	1.33	0.0001	−1.14	0.0300	3.74	–	–	0.0330	2.90
	Total	0.2179	100	−0.0088	100	0.8025	100	0.1264	100	1.1380	100
1992–96 to 1997–2001	Direct effect	0.0035	2.00	0.0081	5.14	0.1032	17.93	0.0577	100	0.1725	17.86
	Indirect effect	0.1697	96.92	0.1471	93.40	0.4600	80.00	–	–	0.7768	80.41
	Interaction	0.0019	1.09	0.0023	1.46	0.0125	2.17	–	–	0.0167	1.73
	Total	0.1751	100	0.1575	100	0.5757	100	0.0577	100	0.9660	100

N, total number of years due to the corresponding effect in each age group.
Direct effect, years of life gained in the age group x, x+n owing to the mortality changes in the group itself.
Indirect effect, years of life gained after the age x+n because of an increased number of survivors (as a result of the mortality changes of the age group x, x+n, assuming that the mortality of the older age groups does not change).
Interaction, years of life gained because of the supplementary survivors at age x+n as a consequence of mortality changes between x and x+n, taking into account that the mortality in the higher age groups also changes.