Table 1.
Characteristics of included studies
| Study | Setting | Eligible participants | Recruitment methods | Authorisation request | Reported outcomes |
|---|---|---|---|---|---|
| Bryant 2006w4 | Cohort study, Canada | English speaking adults aged between 35 and 69 with no known history of cancer, residing in Alberta | Random digit dialling and interview by research team, recruitment period October 2000 to June 2002 | Request for periodic data linkages with Alberta cancer registry and data on utilisation of health services | Age, sex |
| Buckley 2007w5 | Cohort study, Ireland; multicentre (n=35) | Adults with established ischaemic heart disease | Postal survey from researchers, recruitment period not stated (follow-up of CoHeart Study) | Request for access to medical records, survey | Age, sex, income, health status |
| Dunn 2004w7 | Cohort study, UK; multicentre (1-5 centres, depending on study) | Adults meeting eligibility criteria for six different studies | Postal survey (senders unspecified), recruitment period August 1996 to June 2002 | Separate requests for access to medical records and future contact | Age, sex |
| Edlund 1985w8 | Cohort study, USA; single centre | Adult inpatients with tardive dyskinesia | Personal contact in hospital (recruiters unspecified), recruitment period not reported | Request for access to medical records | Age |
| Harris 2004w10 | Cohort study, UK; two centres | Adults aged more than 65 from two London practices | Postal survey (senders unspecified), recruitment period not stated | Separate requests for access to medical records, survey or questionnaire | Age, sex, race, income, health status |
| Huang 2007w11 | Cohort study, Taiwan | Adults aged 20 or more from 2001 Taiwanese National Health Interview Survey with valid identification number | Personal contact by researchers, recruitment period not reported | Request for access to national health insurance records | Age, sex, race, income, education, health status |
| Jacobsen 1999w12 | Registry, USA; single centre | Adult outpatients receiving medical care at Mayo Clinic, Rochester, MN | Postal survey from researchers, recruitment period January to April 1997 | Request for access to medical records | Age, sex, health status (Charlson comorbidity) |
| Klassen 2005; NICU and healthy childrenw13 | Cohort study, Canada; two centres | Children born between 1996 and 1997 in two British Columbia hospitals and three NICUs | Postal survey from researchers, recruitment period not stated | NICU and healthy children; separate requests for access to medical records (mother and baby), survey | Maternal age, sex, income |
| Matsui 2005; non-genetic and geneticw15 | Cohort study, Japan; Takashima study | Adults from geographical catchments in four Japanese areas attending annual health check up | Personal contact by researchers, physicians and nurses, recruitment period 2002-3 | Non-genetic: two catchments, separate requests for access to medical records, survey, blood sample; genetic: two catchments, same as for non-genetic plus genetic analysis, DNA analysis | Sex |
| McKinney 2005w16 | Registry, England; multicentre (n=5) | Children admitted to PICU | Personal contact by PICU staff, recruitment period May to July 2003 | Request for access to medical records | Age, sex, race, income, health status |
| Schwartz 2005w19; Phipps 2004w18 | Registry, USA; three centres | Adults with stroke or traumatic brain injury from 1 of 3 rehabilitation service systems in south eastern Pennsylvania | Personal contact at clinic by “site recruiters”, recruitment period not specified | Separate requests for medical records and future contact | Age, sex, race |
| Tate 2006w20 | Cohort study, UK; Millennium cohort | Children born between September 2000 and January 2002 | Personal contact, recruitment period not stated | Request for access to medical records (mother and baby) | Maternal age, race, income, education |
| Tu 2004; phases I and IIw1 | Registry, Canada; multicentre (n=20), Canadian Stroke Registry Network | Adults with acute stroke, transient ischaemic attacks, or both | Personal contact in hospital by research nurses, two recruitment phases: June 2001 to February 2002, June 2002 to December 2002 | Separate requests for access to medical records, future contact, interview, release of aggregate data to commercial organisation | Age, sex, race |
| Woolf 2000w21 | Registry, USA; single centre | Adults in primary care for practice based research network | Personal contact by clinic administrative staff, recruitment May to November 1999 | Combined request for access to medical records and future contact | Age, sex, race, income, education, health status |
| Yawn 1998w23 | Registry, USA; single centre | Adult and paediatric attendees at medical centre | Personal contact and postal survey (emergency department patients) by administrative clinic staff, recruitment period January to February 1997 | Request for access to medical records | Age, sex |
| Young 2001w24 | Cohort study, Australia; Australian Longitudinal Study on Women’s Health | Women participating in Australian Longitudinal Study on Women’s Health | Postal survey from researchers, recruitment period March 1997 | Request for access to medical records | Age, education |
NICU=neonatal intensive care unit; PICU=paediatric intensive care unit.