The phrase "voluntary based" is correct and usable in written English.
This phrase is typically used to imply that something is taking place or happening based on a person's voluntary or freely chosen action or decision. For example, "Our organization operates on a voluntary based model, so all of our staff members are volunteers."
Participation was voluntary, based on the participant signing a written informed consent form.
As voluntary based researches an application of high Tc superconducting tapes to suppression of plasma vertical instability and a high heat removal system at a divertor are also introduced.
All professional organisations have their own voluntary based medical registry.
We assume 68% of total attrition is involuntary and 32% is voluntary based on a Ministry of Health survey [ 26].
In fact, a voluntary based access instead of a systematic one may have selected those patients with higher prevalence of symptoms and it may explain the higher HPV prevalence observed.
A participatory sensing approach for crowd monitoring faces a major limitation: Participation is based on a voluntary base.
Half of the programmes offered in Europe are voluntary ones [7], whereby the mode of voluntary participation must be seen with caution as offenders are often "forced to participate on a voluntary base" in order to avoid further negative sanctions or measures.
All subjects participate on a voluntary base and receive a small financial compensation (50 euro and travel expenses).
MDGs were agreed on a voluntary base by governments; the new goals should be norms for global governance and to reinforce the concept of the 'right to health'.
Owners and other human house mates of dogs with VL residing in the Netherlands were asked to participate on a voluntary base in this investigation.
Advanced training in palliative care is held on voluntary base, so that the majority of physicians, nurses and other health professions have insufficient palliative care competencies.
