Diligent engagement
Zero people was in fact working in means the analysis question and/or consequences methods, nor was indeed it mixed up in structure and you can implementation https://datingranking.net/es/420-citas/ of the fresh new data.
Research possibilities
Included training was basically randomised managed products when you look at the professionals aged >50 in the baseline with BMD mentioned from the dual opportunity x ray absorptiometry (DXA) or precursor technology like photon absorptiometry. We integrated knowledge you to claimed bone mineral articles (BMC) as BMD was obtained from the breaking up BMC of the bones city and you will plus the several is extremely coordinated. Degree in which very professionals in the baseline got a major systemic pathology other than weakening of bones, such as kidney inability otherwise malignancy, was omitted. We integrated training from calcium used with other medication provided that additional treatment got so you’re able to both of your arms (such as for instance calcium plus nutritional K in the place of placebo in addition to vitamin K), and you will studies out-of co-given calcium and nutritional D products (CaD). Randomised regulated trials out-of hydroxyapatite due to the fact a dietary way to obtain calcium was integrated because it is made from bone and also other nutrients, hormones, protein, and you will amino acids along with calcium. One to journalist (WL otherwise MB) processed titles and you will abstracts, and two authors (WL, MB, otherwise VT) alone screened an entire text from probably related studies. The latest circulate of stuff was found in contour An excellent into the appendix 2.
Data extraction and you can synthesis
We extracted suggestions of for every study from participants’ attributes, analysis construction, financing source and you can issues interesting, and you may BMD on lumbar back, femoral shoulder, complete hip, forearm, and you may complete human anatomy. BMD are going to be mentioned within numerous sites from the forearm, even though the 33% (1/3) radius is actually most often made use of. For every single study, i utilized the stated studies on the forearm, aside from webpages. If the multiple webpages try reported, i made use of the investigation towards site nearest to your 33% distance. An individual writer (VT) removed study, which were appeared because of the the second writer (MB). Chance of bias are analyzed because necessary on Cochrane Guide.eleven One discrepancies were fixed compliment of talk.
The primary endpoints were the percentage changes in BMD from baseline at the five BMD sites. We categorised the studies into three groups by duration: one year was duration <18 months; two years was duration ?18 months and ?2.5 years; and others were studies lasting more than two and a half years. For studies that presented absolute data rather than percentage change from baseline, we calculated the mean percentage change from the raw data and the standard deviation of the percentage change using the approach described in the Cochrane Handbook.11 When data were presented only in figures, we used digital callipers to extract data. In four studies that reported mean data but not measures of spread,12 13 14 15 we imputed the standard deviation for the percentage change in BMD for each site from the average site and duration specific standard deviations of all other studies included in our review. We prespecified subgroup analyses based on the following variables: dietary calcium intake v calcium supplements; risk of bias; calcium monotherapy v CaD; baseline age (<65); sex; community v institutionalised participants; baseline dietary calcium intake <800 mg/day; baseline 25-hydroxyvitamin D <50 nmol/L; calcium dose (?500 v >500 mg/day and <1000 v ?1000 mg/day); and vitamin D dose <800 IU/day.
Analytics
We pooled the data using random effects meta-analyses and assessed for heterogeneity between studies using the I 2 statistic (I 2 >50% was considered significant heterogeneity). Funnel plots and Egger’s regression model were used to assess for the likelihood of systematic bias. We included randomised controlled trials of calcium with or without vitamin D in the primary analyses. Randomised controlled trials in which supplemental vitamin D was provided to both treatment groups, so that the groups differed only in treatment by calcium, were included in calcium monotherapy subgroup analyses, while those comparing co-administered CaD with placebo or controls were included in the CaD subgroup analyses. We included all available data from trials with factorial designs or multiple arms. Thus, for factorial randomised controlled trials we included all study arms involving a comparison of calcium versus no calcium in the primary analyses and the calcium monotherapy subgroup analysis, but only arms comparing CaD with controls in the CaD subgroup analysis. For multi-arm randomised controlled trials, we pooled data from the separate treatment arms for the primary analyses, but each treatment arm was used only once. We undertook analyses of prespecified subgroups using a random effects model when there were 10 or more studies in the analysis and three or more studies in each subgroup and performed a test for interaction between subgroups. All tests were two tailed, and P<0.05 was considered significant. All analyses were performed with Comprehensive Meta-Analysis (version 2, Biostat, Englewood, NJ).
