Table 1.

Application of the SPIDER criteria to the research question and eligibility criteria of the current study

SPIDER criterion	The current study
Sample	Individuals of any age who describe experiences of loneliness, not including specific clinical populations.
Phenomenon of interest	Loneliness.
Design	Any qualitative research design, e.g. interview or focus group. Mixed-methods designs which include qualitative methods will be included if the qualitative findings are reported separately.
Evaluation	Descriptions of experiences of loneliness.
Research type	Primary qualitative research.