Radford L, Bolland M, Mason B, et al. The Auckland calcium study: 5-year post-trial follow-up. Osteoporosis International 2014;25(1):297-304
PubMed link: https://www.ncbi.nlm.nih.gov/pubmed/24114400
Full text article:https://link.springer.com/article/10.1007%2Fs00198-013-2526-z
| Methods | Study design: Non-randomized controlled trial
(parent study was a 5-year, randomized, double-blind, placebo-controlled trial) Number of groups: Four groups |
| Participants | Number of participants: 1408 enrolled, 1174 followed-up
Age: 74.1 ± 4.2 years Sex: 1408 female, 0 male Participants with dementia: No Inclusion criteria: · Female · >55 years, · Were >5 years post-menopause · Normal lumbar spine Bone Mass Density for their age Exclusion criteria: · Receiving treatment for osteoporosis · Taking calcium supplements · Any other major ongoing disease · Serum 25- hydroxyvitamin D levels <25 nmol/L Concomitant medicines: ± medicines Country: New Zealand Setting: Community |
| Interventions | Medicine: Calcium citrate (equivalent to 1g elemental calcium)
Comparison: Placebo Withdrawal schedule: |
| Outcomes | Bone Mass Density
Any fracture Osteoporotic fracture Forearm fracture Vertebral fracture Hip fracture Myocardial infarction Stroke Death |
| Dates | Dates: mid-2008
Follow-up duration: 9.1 ± 2.0. (5 year treatment, and approximately 5 year withdrawal) |
| Funding sources | “This study was funded by the Health Research Council of New Zealand, Greenlane Research Education Fund of New Zealand, Francis and Phyllis Thornell Shore Memorial Scholarship and the Estate of Grace EM Kay Orakau Heart Research Scholarship Trust of New Zealand.” |
| Notes |
Risk of bias table
| Bias | Authors’ judgment | Support for judgment |
| Random sequence generation (selection bias) | High risk | Original study was a randomized controlled trial, but this one was a non-randomized follow-up study. |
| Allocation concealment (selection bias) | 5 out of 5 | This study was an open study. |
| Blinding of participants and personnel (performance bias) | 5 out of 5 | This was an open study. |
| Blinding of outcome assessment (detection bias) | 5 out of 5 | This was an open study. |
| Incomplete outcome data (attrition bias) | 5 out of 5 | The study relied on follow-up data five years after the completion of the study. It was, therefore, reliant on those that could be contacted. |
| Selective reporting (reporting bias) | 1 out of 5 | The study reported all the stated outcomes. |
| Confounding (non-randomized) | 1 out of 5 | This study accounted for participants from both the active and control groups from the original study. It accounted for participants from both the active and control group who had elected to continue calcium supplementation.
“Post-trial calcium use was ascertained during the single telephone call during the post-trial period. If women were taking calcium supplements, they were asked in what form, preparation, and dose and for what duration. Women who reported using more than 4 weeks of calcium supplementation were regarded as post-trial calcium users.Post-trial calcium use was ascertained during the single telephone call during the post-trial period. If women were taking calcium supplements, they were asked in what form, preparation, and dose and for what duration. Women who reported using more than 4 weeks of calcium supplementation were regarded as post-trial calcium users.” |
| Other bias | 5 out of 5 | The study was retrospective and relied on recall rather than on prospective data. |
| Newcastle-Ottawa scale | ||
| Selection bias | Representativeness of the exposed cohort | The cohort is representative of older women in the community. |
| Selection of the non-exposed cohort | Selection of the non-exposed cohort drawn from a different source (originally matched, but now different as they had different interventions in the original study). | |
| Ascertainment of exposure | Ascertainment of exposure was by secure record. | |
| Demonstration that outcome of interest was not present at start of study | Yes, study environment was controlled. | |
| Comparability bias | Comparability of cohorts on the basis of the design or analysis | The study controlled for cessation of active calcium compared to cessation of placebo. |
| Outcome bias | Assessment of outcome | Independent blind assessment. |
| Was follow-up long enough for outcomes to occur | Yes, five years was sufficient. | |
| Adequacy of follow-up of cohorts | subjects lost to follow-up unlikely to introduce bias – small number lost – 84% follow-up.
|
|
Leave a Reply