This study will evaluate the performance and acceptability of different sampling methods for measuring vitamin D, specifically 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃.
This study will evaluate the performance and acceptability of different sampling methods for measuring vitamin D, specifically 25-hydroxyvitamin D₂ and 25-hydroxyvitamin D₃. It will compare results obtained from the routine self-collected dried blood spot (DBS) cards currently in use in our laboratory, with paired capillary and venous serum samples. This compares the collection using three approaches: finger-prick DBS, venepuncture, and the CE-marked Tasso+ upper-arm self-sampling device. The study aims to assess both quantitative agreement between sample types and user acceptability of each collection method.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
SUPPORTIVE_CARE
Masking
NONE
Enrollment
35
Blood collected using Tasso device
Agreement between Tasso+ capillary serum and venous serum 25(OH)D
Continuous 25(OH)D₂ and 25(OH)D₃ concentrations (nmol/L)
Time frame: From Study start date for up to 12 months
User acceptability
Pain, on a scale from 1-5 1= no pain. 5= worse pain
Time frame: From Study start date for up to 12 months
User acceptability
Ease of Use: how easy or difficult each method was to complete 1= Very difficult, 5=Very easy Dried Bloodspot Venepuncture Tasso+
Time frame: From study start date to 12 months
User acceptability
Clarity of Instructions: how clear were the instructions you were given? 1= Not clear at all, 5=Extremely clear Dried Bloodspot Venepuncture Tasso+
Time frame: From Study start date for up to 12 months
User acceptability
Safety: How safe did each method feel to you ? 1= Very unsafe, 5=Very safe Dried Bloodspot Venepuncture Tasso+
Time frame: From Study start date for up to 12 months
User acceptability
Your Preference: please rank the three collection methods 1= your favourite, 3=least preferred Dried Bloodspot Venepuncture Tasso+
Time frame: From Study start date for up to 12 months
User acceptability
Willingness to self-collect: how willing would you be to collect your own sample using each method in the future? 1= Very willing, 5=Very willing Dried Bloodspot Venepuncture Tasso+
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Time frame: From Study start date for up to 12 months
Sample quality
Volume adequacy- minimum blood vol 200uL
Time frame: From Study start date for up to 12 months
Sample quality
Pre analytical failure- % samples unacceptable for analysis due to inadequate volume or poor quality blood spot
Time frame: From Study start date for up to 12 months
Laboratory workflow efficiency
Hands on time (hrs/mins)
Time frame: From Study start date for up to 12 months
Laboratory workflow efficiency
Batch failures based on LCMSMS batch acceptance criteria- QC with +/- 2sd of mean, cal curve R value \> 0.95
Time frame: From Study start date for up to 12 months
Laboratory workflow efficiency
Repeat samples (%)
Time frame: From Study start date for up to 12 months
Turnaround time (TAT)
Time from sample request to result authorisation
Time frame: From Study start date for up to 12 months
Clinical classification agreement
Numerical agreement (statistically quantified by Passing and Bablok analysis)
Time frame: From Study start date for up to 12 months
Clinical classification agreement
Vitamin D status category agreement (deficient / insufficient / replete) quantified statistically using Cohen's kappa analysis
Time frame: From Study start date for up to 12 months