Reasons for Declining Consent in a Population-Based Cohort Study Conducted in a Rural South American Community
Table 2
Procedures and diagnostic tests performed in the population enrolled in the Atahualpa Project cohort and main reasons for refusal.
Diagnostic test
Number (characteristics) of invited individuals
Number (%) of acceptance
Main reasons for refusal
Blood test (year 2013)
616 (aged ≥40 years)
517 (84)
Fear of the needle. Time constraints
Blood test (year 2014)
267 (aged ≥60 years)
220 (82)
Blood test (year 2015)
351 (aged ≥60 years)
259 (74)
Blood test (year 2016)
351 (aged ≥60 years)
319 (90)
Computed tomography
817 (aged ≥40 years)
701 (86)
Time constraints Fear of travel
Magnetic resonance
480 (aged ≥60 years)§
446 (93)
Ankle-brachial index
475 (aged ≥60 years)§
382 (80)
Time constraints Lack of interest
Carotid ultrasounds
691 (aged ≥40 years)
594 (86)
Abdominal ultrasounds
358 (aged ≥40 years)
277 (77)
Transcranial Doppler
90 (aged ≥60 years)‡
73 (81)
Electroencephalograms
180 (aged ≥40 years)‡
163 (91)
Polysomnography
172 (aged ≥40 years)‡
144 (84)
Don’t want to sleep out
24-hour Holter monitoring
315 (aged ≥60 years)
273 (87)
Don’t want to carry the device for 24 hours
Aortic carotid stiffness
330 (aged ≥60 years)
300 (90)
Time constraints Lack of interest
Community lectures (2013)
327 (aged ≥60 years)
228 (70)
Time constraints Lack of interest
Community lectures (2015)
349 (aged ≥60 years)
208 (60)
Community lectures (2017)
338 (aged ≥60 years)¥
312 (92)
Exams performed over different study years. §Invitations also extended to certain individuals aged 40–59 years presenting with specific disorders of interest. ‡Invitations extended to certain individuals according to study design (not population based). ¥Visual acuity determinations and prescription glasses offered to attendants.
