TABLE 3:

Risk of bias

Authors (year)RandomisedControlBlindingFree from vested interestFree of other shortcomingsRisk of bias
Boerms (1981)YABNNPotency unknownHigh
Frerking and Romansky-Rieken (1981)YAB, COMNUNHigh
Day (1984)NUNUIntake unsure, some sows did not receive the full course of medication due to closeness to farrowing, only 20 animals consideredHigh
Day (1986) - trial 1NUNUUneven distribution of animalsHigh
Day (1986) - trial 2YPYUIntake of medication unsureLow
Day (1986) - trial 3NUNUUneven distribution of cows, missing information on remedyHigh
Sonnenwald (1986)YABNUGroups not completely randomised (grazing cows and farmer intervention)High
Seifert (1987)YCONNNUHigh
Stopes and Woodward (1990)NNNUUHigh
Drösemeier (1989)YAB, PYNNHigh
Merck and others (1989)NABNUDifferent times for follow-up checksHigh
Erbe (1990)YPNUUneven distribution, only 42 animals consideredHigh
Tiefenthaler (1990)YAB, COMNUOnly 41 animals consideredHigh
Wirth (1990)YPNUUneven distribution, 42 animals consideredHigh
Schütte (1991) - trial 1YAB, PNUUHigh
Schütte (1991) - trial 2YPNUUHigh
Vohla (1991)NP, UYUUHigh
Knierim (1992)YPYUOnly 30 animals consideredLow
Kayne and Rafferty (1994)YPYU20 animals consideredLow
Schütte (1994) - trial 1YPYUULow
Schütte (1994) - trial 2YPYUULow
Egan (1995)NNNU15 animals consideredHigh
Searcy and others (1995)YPNU26 animals consideredHigh
Guajardo-Bernal and others (1996)YPYUOnly 10 animals consideredHigh
Sandoval and others (1998)YABNUUHigh
Albrecht and Schütte (1999)YP, ABNNUHigh
Hümmelchen (1999)YPYNUHigh
Verdier and others (2003)YPYUULow
Garbe (2003)YAB, P, COMYNUHigh
Schütte (2003)NNNUUHigh
Hektoen and others (2004)YP, ABYUUnknown potencyLow
Schlecht (2004)YPYN39 animals consideredHigh
Holmes and others (2005)YPYUULow
Velkers and others (2005)YU, ABNUUHigh
Berchieri and others (2006)NUNUSelective reporting (exclusion of ineffective remedies tested)High
Walkenhorst (2006)YABNNUHigh
Enbergs and Sensen (2007)YCONNUUHigh
Soto and others (2008)YU, PNUUneven distributed initial weightHigh
Amalcaburio and others (2009)YUNUUHigh
Arlt and others (2009)YPYNUHigh
Coelho and others (2009)YABYU46 animals considered, AB known to be resistant to pathogen in trialHigh
Camerlink and others (2010)YPYUULow
Klocke and others (2010)YU, CONNNUHigh
Werner and others (2010)YP, ABYUULow
Da Silva and others (2011)NNNURemedy data missingHigh
Hadipour and others (2011)YABNUPotency unknownHigh
Kiarazm (2011)YPYUPotency unknownLow
Wagenaar and others (2011)YU, CONNURemedy data missingHigh
Sato and others (2012)YPYUULow
Aubry and others (2013)NNNNResearcher worked for supplierHigh
Hornig (2014)YPYUULow
Williamson and Lacy-Hulbert (2014)YABNUUHigh
  • AB Antibiotics, COM Combined treatment of homeopathy and antibiotics, CON Conventional treatment including antibiotics, N No, P Placebo, U Untreated, Y Yes