First author
|
Year
|
Setting
|
Comparison
|
Study size
|
Participants
|
Risk of Bias
|
Topic
|
Questionnaire description
|
|
|
|
|
|
|
SG±
|
AC"
|
BPP¥
|
BOO§
|
IOD&
|
SR€
|
OSBα
|
|
|
Akl
|
2005
|
US
|
1. Postal vs. Electronic questionnaire
|
202
|
Residents and faculty of the University at Buffalo Internal Medicine Residency program
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Academic issues
|
28 questions (residents), 23 (faculty).
|
Basnov
|
2009
|
Denmark
|
1. Postal vs. Electronic questionnaire
|
782
|
Women referred for mammography
|
Unclear
|
Unclear
|
Unclear
|
Low
|
High
|
High
|
Low
|
Anxiety and Depression
|
Short Form Health Survey and Hospital Anxiety and Depression Scale - 17 pages, 119 items.
|
Bech
|
2009
|
Denmark
|
1. Postal vs. Electronic questionnaire
|
9,900
|
People aged 50-75 years drawn from the Central National Population Register
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Design of nursing homes and facilities
|
35 questions; 16 pages
|
Beebe
|
2018
|
US
|
1. Postal vs. Electronic questionnaire
|
342
|
Primary care clinicians, including physicians, nurse practitioners, and physician assistants
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Clinician knowledge, barriers, and perceived parental barriers regarding HPV vaccination.
|
Questionnaire not described
|
Bergeson
|
2013
|
US
|
1. Postal vs. Electronic questionnaire
|
9,313
|
Patients receiving care at 6 clinics in Minnesota.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
High
|
Low
|
Low
|
Patient experiences with care.
|
CAHPS hybrid survey, 22 questions
|
Bjertnaes
|
2018
|
Norway
|
1. Postal vs. Electronic questionnaire;
2. Electronic only vs. Choice (postal or electronic);
3. Choice (electronic or postal) vs. postal only
|
1,696
|
Parents of children with type 1 diabetes in the Norwegian Childhood Diabetes Registry with at least one outpatient consultation in the previous year.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Parent experiences with their child's diabetes outpatient care.
|
40 questions, 4 pages.
|
Bray
|
2017
|
UK
|
2. Electronic only vs. Choice (postal or electronic)
|
8,765
|
Young people in the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort study
|
Low
|
Low
|
Low
|
Low
|
Low
|
Low
|
Low
|
Gambling, Self-Harm, Employment, Education & Training, Tobacco & Alcohol.
|
A5 booklet of 44 pages; Online questionnaire designed to be similar to the paper questionnaire.
|
Brøgger
|
2007
|
Norway
|
3. Choice (electronic or postal) vs. postal only
|
4,213
|
People aged 20-40 years from the Norwegian Central Population Registry.
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Low
|
Asthma and allergies
|
one-page, 40 questions
|
Clark
|
2011
|
US
|
1. Postal vs. Electronic questionnaire
|
205
|
Director of Nursing and Administrator in nursing homes with at least 30 beds.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Questionnaire not described
|
Questionnaire not described
|
Cobanoglu
|
2001
|
US
|
1. Postal vs. Electronic questionnaire
|
194
|
Hospitality professors with email addresses from members of the Council on Hotel, Restaurant, and Institutional Education.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Hospitality education.
|
Questionnaire not described
|
Fluss
|
2014
|
Scotland, UK
|
1. Postal vs. Electronic questionnaire
|
4,417
|
Residents in Grampian (north of Scotland, UK) aged 25+.
|
Low
|
Low
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Pain and pain management
|
20-pages.
|
Fowler
|
2019
|
US
|
1. Postal vs. Electronic questionnaire
|
4,323
|
Patients age 18+ with at least one primary care visit during previous 6 months, Boston.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
High
|
Low
|
Low
|
Medical care experiences.
|
56 questions, standard CAHPS survey, 12 pages.
|
Hardigan
|
2012
|
US
|
1. Postal vs. Electronic questionnaire;
2. Electronic only vs. Choice (postal or electronic);
3. Choice (electronic or postal) vs. postal only
|
3,953
|
Dentists from the Florida Department of Health, Board of Dentistry.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Tobacco use by dental patients
|
28 questions; 4 pages.
|
Hardigan
|
2016
|
US
|
1. Postal vs. Electronic questionnaire
|
4,661
|
Practicing pharmacists.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Job satisfaction.
|
60 questions; 4 pages.
|
Hohwu
|
2013
|
Denmark
|
2. Electronic only vs. Choice (postal or electronic);
3. Choice (electronic or postal) vs. postal only
|
1,573
|
Parents of children aged 2-17 years
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Children’s health and welfare
|
NordChild questionnaire, 28 pages, 73 questions.
|
Iversen
|
2020
|
Norway
|
2. Electronic only vs. Choice (postal or electronic)
|
6,454
|
Patients aged 16+ registered with a GP.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
User experiences with healthcare.
|
47 questions on 6 pages.
|
Jacob
|
2012
|
US
|
1. Postal vs. Electronic questionnaire
|
556
|
High school principals, Michigan.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Online learning and virtual education
|
42 questions; 15mins completion time
|
Lagerros
|
2012
|
Sweden
|
1. Postal vs. Electronic questionnaire
|
393
|
People from the population register.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Physical activity.
|
4 questions.
|
Leece
|
2004
|
US
|
1. Postal vs. Electronic questionnaire
|
442
|
Surgeon-members of the Orthopaedic Trauma Association
|
High
|
High
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Operative treatment for femoral neck fractures.
|
8 pages
|
Mauz
|
2018
|
Germany
|
1. Postal vs. Electronic questionnaire;
3. Choice (electronic or postal) vs. postal only;
|
6,194
|
Children and adolescents participating in the third wave of the 'German Health Interview and Examination Survey for Children and Adolescents'.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
High
|
Low
|
Low
|
Health care utilisation, living conditions, and environmental determinants of health.
|
Questionnaire not described
|
Millar
|
2011
|
US
|
1. Postal vs. Electronic questionnaire;
2. Electronic only vs. Choice (postal or electronic);
3. Choice (electronic or postal) vs. postal only
|
1,345
|
Undergraduate students at the main campus of Washington State University.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Experiences at University.
|
36 questions.
|
Millar
|
2019
|
US
|
1. Postal vs. Electronic questionnaire
|
470
|
Adults with colorectal, breast, prostate, ovarian, and multiple myeloma cancers, reported in the Utah Cancer Registry.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Cancer recurrence and willingness to participate in cancer research.
|
35 questions.
|
Murphy
|
2020
|
US
|
2. Electronic only vs. Choice (postal or electronic);
|
12,734
|
Physicians from the American Medical Association MasterFile, from haematology or oncology specialties.
|
Low
|
Low
|
Low
|
Low
|
Low
|
Low
|
Low
|
Referral and recruitment of patients to clinical trials and barriers to trial accrual.
|
5-min survey
|
Reinisch
|
2016
|
US
|
1. Postal vs. Electronic questionnaire
|
309
|
Members of the American Association of Plastic Surgeons
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Authorship issues.
|
Questionnaire not described
|
Sakshaug
|
2019
|
Germany
|
1. Postal vs. Electronic questionnaire
|
8,996
|
Public & private establishments that had previously participated in a Job Vacancy Survey and were registered as employing staff in at least one of 25 target professions.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Factors that influence establishments’ decision-making process for filling job vacancies.
|
Questionnaire not described
|
Schmuhl
|
2010
|
US
|
1. Postal vs. Electronic questionnaire;
2. Electronic only vs. Choice (postal or electronic);
3. Choice (electronic or postal) vs. postal only
|
1,178
|
Emergency medical services (EMS) providers with current certification in Utah.
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Low
|
Utah Emergency Services for Children needs assessment.
|
31 questions.
|
Schwartzenberger
|
2017
|
US
|
1. Postal vs. Electronic questionnaire
|
646
|
Patients who underwent endoscopic carpal tunnel release
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Patient-reported outcomes 1 year following carpal tunnel release
|
23 questions
|
Scott
|
2011
|
Australia
|
2. Electronic only vs. Choice (postal or electronic)
|
1,741
|
Doctors undertaking clinical practice drawn from a national directory of doctors.
|
Low
|
Low
|
High
|
Low
|
Low
|
Low
|
Low
|
Balancing Employment & Life -Workforce participation and its determinants among Australian doctors.
|
58 questions, 8 page booklet (specialists in training); 87 questions, 13 page booklet (specialists).
|
Sebo
|
2017
|
Switzerland and France
|
1. Postal vs. Electronic questionnaire
|
3,400
|
Community-based GPs with a valid and available email address
|
Low
|
Low
|
Unclear
|
Low
|
High
|
Low
|
Low
|
GPs' preventive care activities.
|
37 questions.
|
Taylor
|
2019
|
US
|
1. Postal vs. Electronic questionnaire
|
133
|
Individuals aged 6-24 years with smartphones, recruited via Internet to participate in a study about mood and mobile game habits.
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Low
|
Mood, mobile games, and the weather.
|
6 daily multiple-choice questions
|
van den Berg
|
2011
|
Holland
|
2. Electronic only vs. Choice (postal or electronic)
|
277
|
Female survivors of childhood cancer
|
High
|
High
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Reproductive function, ovarian reserve, and risk of premature menopause in female childhood cancer survivors.
|
Department of Epidemiology of the Netherlands Cancer Institute Questionnaire in a cohort study on long-term effects of ovarian stimulation for in vitro fertilization.
|
Weaver
|
2019
|
US
|
1. Postal vs. Electronic questionnaire
|
636
|
Physicians from the Minnesota Board of Medical Practice with both a postal and email address listed.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
High
|
Low
|
Low
|
Factors that influence physicians’ willingness to disclose medical errors and adverse events to patients and their families.
|
Questionnaire not described
|
Whitehead
|
2011
|
New Zealand
|
1. Postal vs. Electronic questionnaire
|
1,914
|
Students randomly selected from a database containing all university students.
|
Low
|
Low
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Anxiety and depression in non-psychiatric populations.
|
41 items.
|
Yetter
|
2010
|
US
|
1. Postal vs. Electronic questionnaire
|
780
|
School psychologists with an email address.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Perceptions of Pre-referral Intervention Teams for addressing children’s school-related academic and behavior difficulties.
|
66 items.
|
Ziegenfuss
|
2010
|
US
|
3. Choice (electronic or postal) vs. postal only
|
770
|
Randomly selected Olmsted County residents aged 25-65.
|
Unclear
|
Unclear
|
Unclear
|
Low
|
Low
|
Low
|
Low
|
Bowel disease.
|
16 pages
|