Table 4

Methods of analysis

Lead Author

Date

Primary outcome measure

Method(s) of Analysis

Gambia Hepatitis Study Group [4]

1987

Liver cancer rates/Vaccine efficacy

Comparisons of incidence rates on a step by step basis to identify vaccine efficacy

Cook [17]

1996

Health Behaviour Questionnaire measures

Comparison of group means and group by time, gender and education interactions (F-test)

Wilmink [19]

1999

Incidence and mortality of RAAAs

Poisson likelihood distribution for incidence rates in person years and maximum likelihood rate ratios

Somerville [14]

2002

Respiratory Health Symptoms

Not stated (description of intervention only)

Fairley [15]

2003

Proportion of missed doses

Unpaired t-test of means

Hughes [12]

2003

Mother to child HIV transmission

Not stated (protocol only)

Levy [16]

2004

Proportion of missed doses

Wilcoxon rank-sum test

Priestly [22]

2004

Rate of in-hospital deaths

Logistic regression Cox proportional hazard models (length of stay)

Bailey [18]

2004

Water quality

Summary statistics only Time series analysis for diarrhoea rates

Grant [20]

2005

TB episodes >90 days after clinic entry

Poisson random effects model

Ciliberto [21]

2005

Attainment WHZ score >-2/Death

95% CI for differences between groups Linear and logistic regression for effects of covariates

Chaisson [13]

2005

TB Incidence

Step by step analysis of incidence Conditional logistic regression Cost-effectiveness analysis

Brown and Lilford BMC Medical Research Methodology 2006 6:54   doi:10.1186/1471-2288-6-54