TABLE 1.

Studies that compare the decline of lung function over time between MM and MZ individuals

First author [ref.]	Year	Average follow-up duration years	Population	Adjustment for confounders	Faster decline in lung function in MZ compared to MM individuals?
de Hamel [59]	1981	3	499 MM compared to 32 MZ individuals from New Zealand	Matched a subgroup of population to adjust for confounders	No
Madison [60]	1981	6	82 MM compared to 42 MZ individuals	Yes	Only in MZ men
Eriksson [63]	1985	6	31 MM compared to 32 MZ individuals	Yes	Only in MZ smokers
Pierre [61]	1988	5	757 MM compared to 21 MZ iron-ore miners	No difference in age, length of employment, or smoking	Yes
Tarján [62]	1994	10	28 nonsmoking matched MM and MZ pairs	Yes	Yes
Sandford [57]	2001	5	283 subjects with rapid decline compared to 308 subjects with no decline in lung function	Yes	More MZ individuals were found in the rapid decline group
Dahl [66]	2002	21	9187 adults randomly selected from the Danish general population: 7037 MM compared to 451 MZ	Yes	Yes
Silva [58]	2003	15	1802 MM compared to 58 MZ individuals selected randomly from an Arizona population	Yes	No
Thun [64]	2012	11	4207 MM compared to 112 MZ individuals	Yes	Only in FEF25–75% among persistent smokers

FEF_25–75%: forced expiratory flow at 25–75% of forced vital capacity.