Methodology and study population of the second Swiss national community survey of functioning after spinal cord injury.

Study Design: Descriptive study of the second community survey of the Swiss Spinal Cord Injury Cohort Study (Survey 2017) conducted between 03/2017 and 03/2018.

Objectives: To describe the methodology, recruitment results, characteristics of participants and non-participants, and non-response of the Survey 2017.

Setting: Community.

Methods: Description of the sampling strategy and sampling frame. Recruitment results and characteristics of participants and non-participants of the two Survey 2017 questionnaire modules were analyzed using descriptive statistics. Determinants of survey participation were examined using multivariable logistic regression, and the impact of non-response bias on survey results was evaluated using inverse-probability weighting.

Results: Out of 3959 persons who met the eligibility criteria, 1530 responded to module 1 (response rate 38.6%) and 1294 to module 2 (response rate 32.7%) of the Survey 2017. Of the 4493 invited persons, 1549 had participated in the first SwiSCI community survey conducted in 2012/2013. Of these, 1332 were invited to the Survey 2017 and 761 participated in module 1 (response rate 58.9%) and 685 in module 2 (response rate 53.1%). The majority of module 1 participants were male (71.2%, 95% CI: 68.9, 73.5), with a median age of 57 (IQR: 46.0, 67.0) years and incomplete paraplegia (41.9%, 95% CI: 39.3, 44.5). Survey non-response was higher in the oldest age group, among females, and those with tetraplegia.

Conclusions: The design of the Survey 2017 was successful in recruiting a substantial proportion of the SCI source population in Switzerland. To counteract survey non-response, survey weights may be applied to subsequent analyses.

Sponsorship: none.