Table 3

Increase in Study Retention Rates for Repeat Questionnaires and Alternative Methods of Data Collection by Data Collection Type

Data Collection Method


Postal

Face-to-Face

Telephone

Mixed


Evaluated Retention Method, reference number

Average increase in retention rate, proportion (95% CI)

Average increase in retention rate, proportion (95% CI)

Average increase in retention rate, proportion (95% CI)

Average increase in retention rate, proportion (95% CI)


Repeat Questionnaires

2 Questionniares Posted

Doody[22]*

0.08 (0.08, 0.08)

Eagan[37]

0.18 (0.17, 0.19)

Hoffman[40]

0.05 (0.04, 0.06)

Rimm[31]

0.16 (0.16, 0.17)

Ullman[48]

0.04 (0.03, 0.06)

3 Questionniares Posted

Clarke[36]

0.18 (0.15, 0.22)

White[33]*

0.06 (0.04, 0.08)

6 Questionnaires Posted

Calle[35]

0.37 (0.37, 0.38)

Russell[46]

0.23 (0.23, 0.23)

Alternative Methods of Data Collection

Postal Questionnaires

Garcia[38]

0.01 (0.01, 0.02)

Mills[43]

0.17 (0.15, 0.19)

Face-to-Face Interviews

Lissner[41]

0.18 (0.16, 0.21)

Tolus so[47]

0.02 (0.02, 0.02)

Telephone Interviews

Boys[34]

0.01 (0.01, 0.03)

Calle[35]

0.02 (0.02, 0.02)

Michaud[42]

0.17 (0.16, 0.18)

Russell[46]

0.02 (0.02, 0.02)

WHA Research Group (YC)[50-53]

0.01 (0.01, 0.01)

WHA Research Group (MC)[50-53]

0.05 (0.05, 0.05)

WHA Research Group (OC)[50-53]

0.08 (0.08, 0.09)

Mixed (Postal, Telephone & Face-to-Face) Novo[44]

0.42 (0.39, 0.44)


Booker et al. BMC Public Health 2011 11:249   doi:10.1186/1471-2458-11-249

Open Data