Table 3

Summary results of quality assessment

Author (year)Data sourceSamplingStatistical reportingFocus
Official*Short and long term Morning and evening Spring and autumn§ Multiple road users Incidence/ mean/SD**Other factors†† Light rather than sleep‡‡
Askenasy26 YNNYNYNN
Chu37 YNYNNYYY
Coate18 YNYYYYYY
Conte27 YNNYNYYN
Coren28 YNNYNYNN
Crawley29 YYNYNNNY
Ferguson9 YNYYYNNY
Green30 YNNYNYNY
Hicks25 YNNYNYYN
Hicks31 YNNYNYNN
Huang16 YYYYNNYY
Lahti32 YNNYNNYN
Lambe33 YNNYNYNN
Meyerhoff17 YYYYNYNY
Sarma and Carey20 YYYYYYYY
Smith34 YNYYNNYY
Sood and Ghosh22 YYNNYYNY
Stevens (2005)?NYYYYNY
Sullivan21 YNYYYYYY
Sullivan38 YNYYYYNY
Sullivan (2003 and 2004)YNNNYYNY
Sullivan6 YNYYNYNY
Varughese36 YNNYNYNN
Whitaker (1996)YNYYYYNY
  • *Data derived from official collision data source such as police or national authority.

  • †Short-term and long-term analyses reported.

  • ‡Separate analyses for morning and evening collisions is more sensitive to DST effects.

  • §Separate analyses for spring and autumn transitions can test hypothesised DST effects for each transition.

  • ¶Separate analyses for different road users is important to the CET debate.

  • **Reporting of incidence and mean/SD would support a meta-analytic review if comparison periods were uniform across studies.

  • ††Reporting data for factors that could explain, in whole or part, collision trends around DST transitions aids interpretation of light effects.

  • ‡‡Papers that focused specifically on light transitions, rather than only on the impact of time changes on sleep duration and latency, were more relevant to our review (if they focused on both sleep and light, they were coded Y).

  • CET, Central European Time; DST. daylight saving time.