In order to ensure representativeness of our sample, we pre-specified inclusion criteria based on a national survey of physicians as follows [21]: We included internists, general surgeons, orthopedic surgeons, pediatricians, obstetrician-gynecologists, psychiatrists, and ophthalmologists because these were the seven most numerous specialties in Japan.
We applied pre-specified eligibility criteria to identify potentially eligible studies.
We pre-specified our criteria for success of the pilot as enrolment of our pilot sample within two years, 70% or greater protocol adherence, and 95% or greater completeness to follow-up.
A decision was also made to pre-specify a uniform criterion across studies for the time point at which to assess event rates.
Many studies (40 of 97) do not pre-specify a target dose criterion.
All data was analyzed according to criteria pre-specified in the study protocol.
This includes pre-specifying the hypotheses, inclusion criteria and outcome measures to be used.
Although this may imply a study selection bias, we pre-specified the study selection criteria, thus minimising such bias.
In interpreting the above findings, the limitations of our study need to be borne in mind [ 34]: (1) We limited our search to specific databases, year ranges and publication media and a number of tight inclusion criteria were pre-specified.
The acylpeptide hydrolase (APEH) SNP rs 4855881 showed a trend toward significance (P=0.0199), but the P-value was still above the B H criterion of 0.011 that we pre-specified as denoting significance.
The inclusion criteria and methods for the review were pre-specified in a protocol (available on request from authors).
