Table 1

Eight plausibly occurring scenarios in terms of starting levels of and relative changes in mortality by socioeconomic group

	Start	Change in mortality	Nr.	Change in RR	Change in RD
Declining mortality	RR>1, RD>0	Δ_h<Δ_l<0	I.a	Rise	Rise as long as RR<Δ_h/Δ_l, then decline
	RR<1, RD<0	Δ_h<Δ_l<0	I.b	Rise to values above 1, then further rise	Rise to values above 0, further rise as long as RR<Δ_h/Δ_l, then decline
	RR>1, RD>0	Δ_l<Δ_h<0	I.c	Decline to values below 1, then further decline	Decline to values below 0, then further decline as long as RR > Δ_h/Δ_l, then rise
	RR<1, RD<0	Δ_l<Δ_h<0	I.d	Decline	Decline as long as RR > Δ_h/Δ_l, then rise
Increasing mortality	RR>1, RD>0	Δ_l>Δ_h>0	II.a	Rise	Rise
	RR<1, RD<0	Δ_l>Δ_h>0	II.b	Rise to values above 1, then further rise	Rise to values above 0, then further rise
	RR>1, RD>0	Δ_h>Δ_l>0	II.c	Decline to values below 1, then further decline	Rise as long as RR > Δ_h/Δ_l, then decline
	RR<1, RD<0	Δ_h>Δ_l>0	II.d	Decline	Decline

Situations in which RD does not increase or decrease monotonically are presented in bold.
For simplicity, we ignore scenarios in which mortality declines in the higher socioeconomic group, but increases in the lower socioeconomic group (and vice versa).
RD, rate difference; RR, rate ratio.