Further concerns include the inadequate use of statistical methods, model comparison when different factors are being investigated and the differing format of factors across studies.
One important reason for this concerns the inadequate use of statistical methods for continuous predictors, such as age or haemoglobin, finally leading to difficulties in comparing multivariable models with different categorisations of the factors (Simon and Altman, 1994).
Besides heterogeneity in patient populations and treatments between different studies, a substantial reason for the observed variation might be attributable to an inadequate use of statistical methods (Simon and Altman, 1994).
Established methods were used to appraise individual study quality, although it was sometimes difficult to reliably distinguish between genuinely poor-quality data collection and analysis versus inadequate reporting of methods.
Discrepancies in the findings of different investigators could be due to variable and often inadequate duration of intervention and use of different methods to measure insulin sensitivity.
Inadequate access to contraceptive methods, method failure caused by misuse of the methods and non-use of effective methods are the reasons of unwanted pregnancies, which lead women to induced abortion [ 1].
Consequently, multiple statistical testing of several endpoints without or with only insufficient adjustment of the chosen significance level, or the use of inadequate statistical methods [21, 69 71].
Inadequate planning and forecasting, use of archaic procurement methods, and tendering yearly or multiple times a year contribute to high commodity costs, long lead times, stock imbalances, and, overall, commodity insecurity.
Experts blame the irreproducibility problem on a number of factors, including inadequate reporting of the methods used in published research studies.
With regard to selection, the first quality assessment domain of the NOS, nine cross-sectional studies were deemed subject to bias due to the nonrepresentativeness of the population (individuals with type 2 diabetes in the workforce; 6, 15, 16, 21, 28– 32), as were eight cross-sectional studies due to use of an inadequate method for ascertaining diabetes (15, 16, 21, 28– 33, 33).
Other factors include a lack of stringent criteria for contraceptive use and consequently use of unreliable contraceptive methods, inadequate counseling of participants during the informed consent process and a lack of contraceptive services at trial sites.
