Zero people was basically employed in setting the study matter or the outcome procedures, neither was in fact it involved in the design and you can implementation of the fresh new research.
Included training was basically randomised controlled trials within the members aged >fifty from the baseline with BMD measured by dual times x-ray absorptiometry (DXA) or precursor technology particularly photon absorptiometry. We incorporated degree you to claimed bone nutrient blogs (BMC) as the BMD try gotten by the separating BMC by bones city and you can additionally the several was highly coordinated. Education where really users from the standard had a primary systemic pathology except that weakening of bones, such as for instance renal incapacity or most cancers, was basically excluded. I included studies out-of calcium used with almost every other cures provided others medication got so you’re able to both of your arms (like calcium in addition to nutritional K instead of placebo and nutritional K), and you may degree out of co-given calcium and you will vitamin D tablets (CaD). Randomised regulated trials out of hydroxyapatite since the a diet supply of calcium had been incorporated because it’s produced from bone and has most other vitamins, hormones, protein, and you can amino acids along with calcium. One journalist (WL gleeden incelemesi otherwise MB) screened headings and abstracts, and two article writers (WL, MB, or VT) individually screened an entire text out-of probably associated training. The new flow away from articles is found during the contour An effective inside appendix dos.
Investigation extraction and you can synthesis
I removed recommendations away from for every study from participants’ properties, analysis design, resource supply and disputes of great interest, and you will BMD during the lumbar back, femoral neck, overall cool, forearm, and you can overall human anatomy. BMD will likely be measured at multiple internet sites regarding forearm, whilst 33% (1/3) radius try most frequently utilized. Each investigation, we made use of the advertised data to your forearm, no matter site. When the one or more site try advertised, i used the data into webpages nearest to the 33% distance. An individual journalist (VT) removed analysis, that have been seemed of the an additional publisher (MB). Likelihood of bias is actually reviewed while the demanded about Cochrane Guide.11 Any discrepancies were resolved as a result of dialogue.
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 500 mg/day and <1000 v ?1000 mg/day); and vitamin D dose <800 IU/day.
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).