Summary of Reserved Samples


All of the baseline serum collection is considered reserved, due to both scarcity and increased scientific value. For all visit years vials can be identified individually, as reserved or not, based on the combination of two fields:

  • “Clean Post” indicating whether or not this participant would go on to have a natural menopause transition (defined as ‘not reporting any Hormone Therapy use before or at the first visit she was classified as post-menopausal’).
  • “Scarcity” or Vial Count per Visit.

The following table shows the cut off points for reserving samples based on these two values.

Clean Post = No 2-5 vials left Reserved
Clean Post = Yes 2-10 vials left Reserved
(either) 1 vial left Restricted

Women with a clean transition have a higher scientific value and therefore vial counts of 10 vials or fewer per visit year are flagged as reserved, where serum from women without a clean transition are flagged at 5 vials or fewer. The last vial left for any woman is flagged as restricted.


All plasma vials are considered reserved due to scarcity. At baseline there is only 1 EDTA and 1 Citrate Plasma vial per woman, on average. In later visit years, there are not more than 4 vials per woman per year.

Plasma is also expected to become a more utilized, and therefore valuable, specimen type.


Not reserved, plentiful.


Not reserved, renewable.

Guidelines for Use of Reserved Samples

  • Reserved samples should not be used if the question can be answered using other available samples.
    • Other available samples include non-reserved SWAN samples from other comparable women, from different time points, and/or non-pristine samples.
  • Reserved samples should not be used for exploratory investigations or very preliminary hypothesis testing.
    • Prior scientific evidence should exist to justify the hypothesis/proposed analyses.
  • Reserved samples should be used to substantively advance scientific knowledge and for innovative science.
  • The use of Reserved samples should be more strongly considered for studies that are consistent with the mission of SWAN.