| Study | Reason for exclusion |
| ABD EL-HAKEEM EE 2003 | No linear pain scale |
| ALEX J 2003 | Not randomised |
| AUGOUSTIDES JG 2001 | Review |
| AYED AK 2000 | No linear pain scale |
| AZAD SC 2000 | Not English |
| BACHIOCCO V 2001 | Not a comparative clinical trial |
| BADNER NH 1989 | Not a comparative clinical trial |
| BADNER NH 1992 | Subgroups not defined |
| BADNER NH 1994 | Subgroups not defined |
| BAUMRUCKER SJ 2002 | Review |
| BEDI JP 2003 | No VAS scores |
| BENEDETTI F 1998 | Not a comparative study for pain with different regimens, comparison of effectiveness of one drug in same patients at different times. |
| BENUMOF JL 1987 | No linear pain scale |
| BERGH NP 1966 | No linear pain scale |
| BLOCK BM 2003 | Review, meta-analysis |
| BOLDT J 1996 | No linear pain scale |
| BORMANN B 1983 | Subgroups not defined, no linear pain scale |
| BROSE WG 1991 | No comparison of analgesic regimens |
| BURGESS FW 1993 | No comparison of pain scores between randomised groups. |
| CERFOLIO RJ 2003 | Not randomised |
| CHAN V 1988 | Not a comparative clinical trial |
| CHAN VWS 1989 | Abstract only |
| CHATHAM K 1993 | No linear pain scale |
| CHELLY JE 2004 | Mixed surgery, subgroups not defined. |
| CONACHER ID 1990 | Review |
| DE LA ROCHA AG 1984 | No linear pain scale |
| DELILKAN AE 1973 | No linear pain scale |
| DELLINGER A 1988 | Not English |
| DIEGELER A 1999 | Not randomised |
| ENG J 1993 | Review |
| ETCHES RC 1989 | Abstract only |
| FAUST RJ 1976 | No linear pain scale |
| FORSTER R 2002 | Not randomised |
| FRANCOIS T 1995 | Thoracotomy and upper abdominal incision |
| FROMME GA 1985 | Retrospective |
| FURRER M 1997 | Not randomised |
| GALWAY JE 1975 | No linear pain scale |
| GARUTTI I 2003 | No linear pain scale |
| GEBHARD FT 1996 | No linear pain scale |
| GIUDICELLI R 1994 | Not randomised |
| GLANTZ L 2004 | Not randomised |
| GLYNN CJ 1980 | Not randomised |
| GORDH T 1988 | No linear pain scale |
| GOWAN JD 1988 | Study of naloxone, which is not relevant to the review |
| GOZAL Y 1999 | Review |
| GRANELL GIL M 2000 | Not English |
| GRANT RP 1990 | Abstract only |
| GRAY JR 1986 | No linear pain scale, randomisation not clear |
| GRIFFITHS DPG 1975 | No linear pain scale |
| GROSMANOVA T 1993 | No linear pain scale |
| GUNDERSEN RY 1986 | Subgroups not defined |
| HAAK VAN DER LELY 1994B | No linear pain scale |
| HAAK-VAN DER LELY 1993 | No linear pain scale |
| HAAK-VAN DER LELY 1994 | No linear pain scale |
| HACHENBERG T 1999 | Review |
| HANSDOTTIR V 1996b | Same patients as Hansdottir V 1996a, pharmacokinetics study. Analgesic info in other paper. |
| HASENBOS M 1985 | No linear pain score |
| HASENBOS M 1985B | No linear pain scale |
| HASENBOS M 1987 | No linear pain scale |
| HASENBOS MAWM 1989 | Not randomised |
| HAYWARD RH 1994 | Not randomised, retrospective |
| HIGGINS TL 1994 | No linear pain scale |
| INADA K 2000 | Not randomised |
| INDERBITZI R 1992 | No linear pain scale |
| IWASAKI A 2004 | Not randomised |
| JAIN S 1999 | Review |
| JAKOBSEN CJ 1997 | No linear pain scale |
| JAKOBSEN CJ 1997B | No linear pain scale |
| JIMENEZ-MERCHAN 1997 | Retrospective |
| JOHNSON MD 1990 | No linear pain scale |
| JONES RM 1985 | Study of lysine acetyl salicylate, which is no longer available |
| JOUCKEN K 1987 | No linear pain scale |
| KATZ J 1996 | Not a comparative clinical trial |
| KAVANAGH BP 1992 | Abstract only |
| KESSLER P 2002 | Not randomised |
| KIM KH 1996 | Not randomised |
| KIRBY TJ 1995 | No linear pain scale scores |
| KISS J 1976 | Not randomised comparative trial |
| KOLVENBACH H 1989 | Not randomised |
| KOREN G 1989 | Same data as Whiting 1988 (but less detail) |
| KOVACS M 1971 | Not randomised, no linear pain scale |
| KRUGER M 1999 | Review |
| KRUGER M 1999B | Review |
| LANDRENEAU RJ 1996 | Not randomised |
| LANGE MP 1988 | No linear pain scale |
| LAXENAIRE MC 1986 | No linear pain scale |
| LEBOVITS AH 2001 | Subgroups not defined |
| LEPAGE-SAVARY D 1991 | Subgroups not defined |
| LI WWL 2003 | Not randomised |
| LIEOU FJ 1996 | Not thoracotomy |
| LUDWICK F 1995 | Paediatric |
| MASCOTTO G 2003 | No linear pain scale |
| MATSUMURA Y 2000 | Not English |
| MCCRORY C 2004 | Repeat data from McCrory C 2002, focus on prostaglandin formation |
| MOON MR 1999 | Thoracic injury, not thoracotomy surgery |
| MOOTE C 1992 | Review |
| MURPHY DF 1994 | Abdominal and thoracic surgery |
| NELSON KM 1974 | No linear pain scale |
| NORDBERG G 1983 | No linear pain scale |
| NORDBERG G 1984 | No linear pain scale |
| NORDBERG G 1986 | No linear pain scale |
| NORDBERG G 1987 | No linear pain scale |
| NORDBERG G 1988 | No linear pain scale |
| NOVAK-JANKOVIC 2000 | No linear pain scale |
| OAKES DD 1982 | Not randomised study |
| ORR IA 1983 | Not fully randomised, extension of 1981 study |
| PANOS L 1990 | Abstract only |
| PETIT J 1988 | Not English |
| PHILLIPS DM 1984 | Not randomised |
| PIGOT B 1987 | Not English |
| POOPALALINGAM R 2003 | Thoracic and upper abdominal surgery, subgroups not defined for results. |
| POWER I 1990 | No linear pain scale |
| QUIMBY CW 1966 | No linear pain scale |
| RAFF H 1988 | No linear pain scale |
| RAGNI J 1991 | Not English |
| RANDELL TT 1991 | No linear pain scale |
| RAWAL N 1981 | Not a comparative trial |
| RICHARDSON J 1999B | Review |
| RICHARDSON J 1999C | Review |
| ROONEY SM 1983 | No linear pain scale |
| ROONEY SM 1986 | No linear pain scale |
| ROSENBERG PH 1987 | Not a comparative trial |
| RUBIN JW 1994 | Not randomised |
| RUBIN JW 1994B | Not randomised, comparative trial |
| SABANATHAN S 1995 | Not a comparative clinical trial |
| SABANATHAN S 1995b | Study data published in more detail in Richardson J 1994 |
| SALOMAKI TE 1993 | Data published in Salomaki TE 1991 (pain data in more detail there) |
| SALZER GM 1997 | Not randomised |
| SANDLER AN 1999 | Review |
| SATOH M 2000 | Not English |
| SATOH M 2001 | Not English |
| SAVAGE C 2002 | Review |
| SAVOIA G 2001 | Review |
| SCHULTZ AM 1997 | Not a comparative study |
| SEKINE Y 1999 | No linear pain scale |
| SOFIANOS E 1985 | No linear pain scale |
| STENSETH R 1985 | No linear pain scale |
| STRATTON SA 1980 | No linear pain scale |
| SUBRAMANIAM B 2000 | Subgroups not defined |
| SUGIURA H 1999 | Retrospective |
| SULEK CA 2000 | Subgroups not defined |
| SUTTON BA 1994 | Abstract only |
| SUWANCHINDA V 2000 | Not randomised |
| TAKAHASHI N 2001 | Not English |
| TARTIERE J 1991 | Thoraco-abdominal surgery |
| TENLING A 1999 | No linear pain scale |
| TOLEDO-PEREYRA 1979 | No linear pain scale |
| TOVAR EA 1998 | Not a comparative clinical trial |
| TRINDER TJ 1998 | No linear pain scale |
| TSUI SL 1991 | Thoracic plus abdominal incision |
| UEDA M 1999 | No linear pain scale |
| URSCHEL HC 1986 | Not randomised |
| USUI A 2001 | Not randomised, retrospective |
| VARA-THORBECK VR1987 | Not English |
| WALLER DA 1994 | No linear pain scale |
| WIEBALCK A 1997 | Subgroups not defined |
| WIED U 1981 | Thoracoscopy, not thoracotomy |
| WILHELM AJ 1993 | Subgroups not defined |
| WILLDECK-LUND G 1975 | No linear pain scale |
| WULF H 1998 | No linear pain scale |
| YIM APC 2000 | Not randomised |
| ZAWADZKI A 1997 | Not randomised, comparative study |