|  |  |  | Severityc(%) | |||
---|---|---|---|---|---|---|---|
Study population | Country (sample size) | Criteria | Ageb(yr) | Stage 1 | Stage 2 | Stage 3 | Stage 4 |
General population | |||||||
   Buist et al., 2007 [8] | Austria (1,349) | GOLD 2006 | ≥40 | 59.4 | 35.2 | 5.4 | |
 | Germany (713) |  |  | 55.3 | 38.6 | 6.1 | |
 | Poland (603) |  |  | 50.7 | 40.7 | 8.6 | |
 | Norway (707) |  |  | 55.8 | 37.8 | 6.4 | |
   Shahab et al., 2006 [29] | United Kingdom (8,215) | GOLD 2006 | 55.5 (13.5) | 41.6 | 43.9 | 14.5 | |
   Lindberg et al., 2006 [47] | Sweden (1,237) | GOLD 2006 | 46-77 | 57.0 | 37.0 | 5.0 | 1.0 |
 |  | BTS 1997 |  | 65.0 | 27.0 | 8.0 | NA |
   De Marco et al., 2004 [48]d | Belgium (1,122) | GOLD 2003 | 20-44 | 58.6 | 41.4 | ND | |
 | Denmark (394) |  |  | 56.4 | 43.6 | ND | |
 | France (2,137) |  |  | 66.7 | 33.3 | ND | |
 | Germany (1,983) |  |  | 64.8 | 35.2 | ND | |
 | Italy (910) |  |  | 69.4 | 30.6 | ND | |
 | Ireland (454) |  |  | 75.3 | 24.7 | ND | |
 | Netherlands (1,362) |  |  | 74.3 | 25.7 | ND | |
 | Norway (969) |  |  | 40.7 | 59.3 | ND | |
 | Spain (1,942) |  |  | 59.2 | 40.8 | ND | |
 | Sweden (1,859) |  |  | 79.3 | 20.7 | ND | |
 | Switzerland (853) |  |  | 76.3 | 23.7 | ND | |
 | United Kingdom (1,198) |  |  | 69.8 | 30.2 | ND | |
   Tzanakis et al., 2004 [33] | Greece (888) | ERS 1995 | ≥35 | 58.2 | 25.6 | 16.2 | NA |
   Jansson et al., 2002 [49] | Sweden (212) | BTSe | 28-29 | 75.0 | 25.0 | 0 | 0 |
 |  |  | 43-44 | 46.6 | 46.6 | 6.8 | 0 |
 |  |  | 49-50 | 16.0 | 64.0 | 12.0 | 8.0 |
 |  |  | 58-59 | 15.4 | 57.7 | 15.4 | 11.5 |
 |  |  | 64-65 | 6.9 | 29.3 | 41.4 | 22.4 |
 |  |  | 73-74 | 14.3 | 21.4 | 47.6 | 16.7 |
 |  |  | 79-80 | 9.8 | 34.2 | 48.8 | 7.3 |
   Viegi et al., 2000 [36] | Italy (1,727) | ERS 1995 | ≥25 | 81.0 | 14.0 | 5.0 | NA |
 |  | ATS 1995 |  | 98.2 | 1.8 | 0 | NA |
 |  | Clinicalf |  | 86.1 | 13.9 | ||
   Von Hertzen et al., 2000 [50]g | Finland (7,217) |  | ≥30 | 59.8 | 34.1 | 6.1 | NA |
General practitioner and/or chest specialist | |||||||
   Izquierdo et al., 2009 [51] | Spain (3,619) | GOLD 2006 | 67.0 (10.8) | 20.1 | 54.0 | 22.1 | 3.8 |
   Bednarek et al., 2008 [27] | Poland (1,960) | GOLD 2006 | 56.7 (11.6) | 30.6 | 51.4 | 15.3 | 2.7 |
   Hoogendoorn et al., 2006 [52] | Sweden (481) | GOLD 2006 | 65.5 | 30.0 | 51.0 | 17.0 | 2.0 |
   Piperno et al., 2005 [14] | France (3,411) | SPLF 1996 | 58.4 (9.9) | 31.3 | 50.2 | 18.5 | NA |
   Detournay et al., 2004 [53] | France (255) | SPLF 1996 | 67.1 | 56.0 | 27.0 | 17.0 | NA |
   Soriano et al., 2000 [54] | United Kingdom (23,277) | Prescriptions | 66.7 (15.5) | 35.5 | 56.4 | 8.1 | NA |
Hospital | |||||||
   Soler-Cataluña et al., 2005 [55] | Netherlands (304) | GOLD 2006 | 71 (9) | 6.6 | 35.8 | 33.6 | 24.0 |
   Tsoumakidou et al., 2004 [56] | Greece (67) | ERS 1995 | 69.0 | 0 | 4.5 | 95.5 | NA |
 |  | BTS 1997 | 69.5 | 1.5 | 14.9 | 83.6 | NA |
 |  | ATS 1995 | 67.6 | 4.5 | 28.3 | 67.2 | NA |
 |  | GOLD 2001 | 69.5 | 0 | 58.2 | 41.8 | |
   Kornmann et al., 2003 [57] | Germany (1,434) | GOLD 2001 | {55} | 7.9 | 73.0 | 19.1 |