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Table 1 Response and participation rate in the Nightingale Study

From: The Nightingale study: rationale, study design and baseline characteristics of a prospective cohort study on shift work and breast cancer risk among nurses

 

N (%)

Eligible and invited

192,931

  Response received (responders)

76,932 (40%)

  No response received

115,039 (60%)

  Lost to follow-up (mail returned undeliverable)

960 (<1%)

Responders

 

  Declined participation

3,526 (2%)

  Questionnaire completeda (participants)

59,947 (31%)b

  Incomplete questionnairec

13,459 (7%)

Participants

 

  Questionnaire only

36,508 (61%)

  Questionnaire and toenail sample

23,439 (39%)

  1. a Includes 4,889 women who filled in at least half of the questionnaire (i.e. the most important part on occupational and other risk factors) but did not complete the entire questionnaire.
  2. b Includes 179 women who participated through the self-registration system.
  3. c Women who did completed less than half of the questionnaire.