TABLE 3:
Risk of bias
| Authors (year) | Randomised | Control | Blinding | Free from vested interest | Free of other shortcomings | Risk of bias |
|---|---|---|---|---|---|---|
| Boerms (1981) | Y | AB | N | N | Potency unknown | High |
| Frerking and Romansky-Rieken (1981) | Y | AB, COM | N | U | N | High |
| Day (1984) | N | U | N | U | Intake unsure, some sows did not receive the full course of medication due to closeness to farrowing, only 20 animals considered | High |
| Day (1986) - trial 1 | N | U | N | U | Uneven distribution of animals | High |
| Day (1986) - trial 2 | Y | P | Y | U | Intake of medication unsure | Low |
| Day (1986) - trial 3 | N | U | N | U | Uneven distribution of cows, missing information on remedy | High |
| Sonnenwald (1986) | Y | AB | N | U | Groups not completely randomised (grazing cows and farmer intervention) | High |
| Seifert (1987) | Y | CON | N | N | U | High |
| Stopes and Woodward (1990) | N | N | N | U | U | High |
| Drösemeier (1989) | Y | AB, P | Y | N | N | High |
| Merck and others (1989) | N | AB | N | U | Different times for follow-up checks | High |
| Erbe (1990) | Y | P | N | U | Uneven distribution, only 42 animals considered | High |
| Tiefenthaler (1990) | Y | AB, COM | N | U | Only 41 animals considered | High |
| Wirth (1990) | Y | P | N | U | Uneven distribution, 42 animals considered | High |
| Schütte (1991) - trial 1 | Y | AB, P | N | U | U | High |
| Schütte (1991) - trial 2 | Y | P | N | U | U | High |
| Vohla (1991) | N | P, U | Y | U | U | High |
| Knierim (1992) | Y | P | Y | U | Only 30 animals considered | Low |
| Kayne and Rafferty (1994) | Y | P | Y | U | 20 animals considered | Low |
| Schütte (1994) - trial 1 | Y | P | Y | U | U | Low |
| Schütte (1994) - trial 2 | Y | P | Y | U | U | Low |
| Egan (1995) | N | N | N | U | 15 animals considered | High |
| Searcy and others (1995) | Y | P | N | U | 26 animals considered | High |
| Guajardo-Bernal and others (1996) | Y | P | Y | U | Only 10 animals considered | High |
| Sandoval and others (1998) | Y | AB | N | U | U | High |
| Albrecht and Schütte (1999) | Y | P, AB | N | N | U | High |
| Hümmelchen (1999) | Y | P | Y | N | U | High |
| Verdier and others (2003) | Y | P | Y | U | U | Low |
| Garbe (2003) | Y | AB, P, COM | Y | N | U | High |
| Schütte (2003) | N | N | N | U | U | High |
| Hektoen and others (2004) | Y | P, AB | Y | U | Unknown potency | Low |
| Schlecht (2004) | Y | P | Y | N | 39 animals considered | High |
| Holmes and others (2005) | Y | P | Y | U | U | Low |
| Velkers and others (2005) | Y | U, AB | N | U | U | High |
| Berchieri and others (2006) | N | U | N | U | Selective reporting (exclusion of ineffective remedies tested) | High |
| Walkenhorst (2006) | Y | AB | N | N | U | High |
| Enbergs and Sensen (2007) | Y | CON | N | U | U | High |
| Soto and others (2008) | Y | U, P | N | U | Uneven distributed initial weight | High |
| Amalcaburio and others (2009) | Y | U | N | U | U | High |
| Arlt and others (2009) | Y | P | Y | N | U | High |
| Coelho and others (2009) | Y | AB | Y | U | 46 animals considered, AB known to be resistant to pathogen in trial | High |
| Camerlink and others (2010) | Y | P | Y | U | U | Low |
| Klocke and others (2010) | Y | U, CON | N | N | U | High |
| Werner and others (2010) | Y | P, AB | Y | U | U | Low |
| Da Silva and others (2011) | N | N | N | U | Remedy data missing | High |
| Hadipour and others (2011) | Y | AB | N | U | Potency unknown | High |
| Kiarazm (2011) | Y | P | Y | U | Potency unknown | Low |
| Wagenaar and others (2011) | Y | U, CON | N | U | Remedy data missing | High |
| Sato and others (2012) | Y | P | Y | U | U | Low |
| Aubry and others (2013) | N | N | N | N | Researcher worked for supplier | High |
| Hornig (2014) | Y | P | Y | U | U | Low |
| Williamson and Lacy-Hulbert (2014) | Y | AB | N | U | U | High |
AB Antibiotics, COM Combined treatment of homeopathy and antibiotics, CON Conventional treatment including antibiotics, N No, P Placebo, U Untreated, Y Yes