These outcomes advance the current underst and ing of Ca digestibility and utilisation , and should contribute towards establishing requirements for digestible Ca .
Consequently , pig diets will be more correctly formulated if digestible Ca values are used in estimating requirements for Ca
Ca digestibility and utilisation in growing pigs are not well understood , and are usually neglected in diet formulation .
This has implication s not only for the accurate determination of its requirements but also for its interactions with other nutrients .
A systematic review and meta- analysis ( meta-regression ) of published trials was carried out to quantify factors affecting Ca absorption and utilisation , and to derive an estimate of Ca endogenous excretion .
Identification of randomized controlled trials in systematic reviews: accuracy and reliability of screening records.
A study was conducted to estimate the accuracy and reliability of  review ers when screening records for relevant trials for a systematic review . A sensitive search of ten electronic bibliographic data bases yielded 22 571 records of potentially relevant trials . Records were allocated to four review ers such that two review ers examined each record and so that identification of trials by each review er could be compared with those identified by each of the other review ers . Agreement between review ers was assessed using Cohen 's kappa statistic . Ascertainment intersection methods were used to estimate the likely number of trials missed by review ers . Full copies of reports were obtained and assessed independently by two research ers for eligibility for the review . Eligible reports formed the ' gold st and ard ' against which an assessment was made about the accuracy of screening by review ers . After screening , 301 of 22 571 records were identified by at least one review er as potentially relevant . Agreement was ' almost perfect ' ( kappa>0.8 ) within two pairs , ' substantial ' ( kappa>0.6 ) within three pairs and ' moderate ' ( kappa>0.4 ) within one pair . Of the 301 records selected , 273 complete reports were available . When pairs of review ers agreed on the potential relevance of records , 81 per cent were eligible ( range 69 to 91 per cent ) . If review ers disagreed , 22 per cent were eligible ( range 12 to 45 per cent ) . Single review ers missed on average 8 per cent of eligible reports ( range 0 to 24 per cent ) , whereas pairs of review ers did not miss any ( range 0 to 1 per cent ) . The use of two review ers to screen records increased the number of r and omized trials identified by an average of 9 per cent ( range 0 to 32 per cent ) . Review ers can reliably identify potentially relevant records when screening thous and s of records for eligibility . Two review ers should screen records for eligibility , whenever possible , in order to maximize ascertainment of relevant trials
These outcomes advance the current underst and ing of Ca digestibility and utilisation , and should contribute towards establishing requirements for digestible Ca .
Consequently , pig diets will be more correctly formulated if digestible Ca values are used in estimating requirements for Ca
Ca digestibility and utilisation in growing pigs are not well understood , and are usually neglected in diet formulation .
This has implication s not only for the accurate determination of its requirements but also for its interactions with other nutrients .
A systematic review and meta- analysis ( meta-regression ) of published trials was carried out to quantify factors affecting Ca absorption and utilisation , and to derive an estimate of Ca endogenous excretion .