Age as the time dimension:
Developmental and behavioural associations of burns and scalds in children: a prospective population-based study
Alan Emond1, Clare Sheahan2, Julie Mytton3, Linda Hollén1
Arch Dis Child. 2017 May;102(5):428-483. doi: 10.1136/archdischild-2016-311644. Epub 2016 Nov 13
Research Question. Investigators wanted to understand child developmental and behavioral characteristics and risk of burns and scalds.
Study sample. 12,966 participants up to age 11 from the Avon Longitudinal Study of Parents and Children.
Longitudinal design. Preinjury profiles of the children derived from material questionnaires completed in pregnancy, and at 6, 18, 42, 47, and 54 months. Injury data collected by questionnaire at 6,15, and 24 months, and 3.5, 4.5, 5.5, 6.5, 8.5, and 11 years of age.
Analysis approach. Authors calculated a period prevalence and an incidence rate, and used a multivariable logistic regression to control for confounders.
Time since study enrollment as the time dimension:
Diabetes incidence and influencing factors in women with and without gestational diabetes mellitus: A 15 year population-based follow-up cohort study
Sonia Minooeea, Fahimeh Ramezani Tehrania, Maryam Rahmatib, a, Mohammad Ali Mansourniab, Fereidoun Azizic
Diabetes Res Clin Pract. 2017 Apr 8;128:24-31. doi: 10.1016/j.diabres.2017.04.003. [Epub ahead of print]
Research Question. Investigators wanted to determine if the incidence of diabetes was greater in women with gestational diabetes compared to those without gestational diabetes.
Study sample. 476 women with gestational diabetes and 1982 women without diabetes were selected from participants of the Tehran Lipid and Glucose study.
Longitudinal design. Participants undergo a follow-up at 3-year intervals, and the study began in 1998 and has continued for 15 years.
Analysis approach. The age-adjusted overall time to development of type 2 diabetes was calculated using a Kaplan-Meier curve. Pooled logistic regression was used to assess the odds ratio between time-dependent covariates age, BMU, and baseline family history of diabetes and GDM and type 2 diabetes.
Neither Age nor Time since study enrollment as the time dimension:
Motivational and contextual determinants of HPV-vaccination uptake: A longitudinal study among mothers of girls invited for the HPV-vaccination
Mirjam Pota, b, , , Hilde M. van Keulenb, Robert A.C. Ruitera, Iris Eekhoutb, Liesbeth Mollemac, Theo W.G.M. Paulussenb
Prev Med. 2017 Apr 4;100:41-49. doi: 10.1016/j.ypmed.2017.04.005. [Epub ahead of print]
Research Question. Investigators would like to know whether HPV-vaccination intention, as well as other social psychological determinants, are good predictors of future HPV-vaccination uptake in a longitudinal design.
Study Population. Random sample of mothers of girls invited for vaccination in 2015 from Praeventis (Dutch vaccination register) and from three online panels.
Longitudinal design. Baseline was a questionnaire given Jan 2015, before the HPV round. After completing the vaccination round, data about girls’ actual HPV-vaccination uptake were derived from Praeventis. Questionnaires were then given to determine what attitudes led to HPV-vaccination. The time element is time from HPV-vaccination round.
Analysis approach. Authors used a multivariate linear regression analysis to assess the total amount of variance explained in HPV-vaccination intention.