Table 3

Limitations associated with study outcomes in 16 studies reviewed




Not randomised [24,27]

No control group [28]

Short duration of the intervention [[15], 1623]


Sample not representative [22,23]

Small sample size [28]

Sampling population restricted to patients who accessed hospital web page [30]

Intervention effect

Unable to determine intervention component contributing to the observed change [23,29]

Unmeasured variable contributing to observed change [28]

Possibility of increased attention to management contributing to observed change [19,20]

Mean baseline HbA1c close to 7% [17,20,25]

Concomitant exposure to another intervention [27]

Participant dropout

Non-random participant dropout [19]

Complete data not available for all participants [29]

Costa et al. BMC Family Practice 2009 10:72   doi:10.1186/1471-2296-10-72

Open Data