The phrase "and difficult to include" is correct and usable in written English.
It can be used when discussing something that poses a challenge or complication in terms of inclusion or integration into a larger context.
Example: "The new regulations are complex and difficult to include in our existing framework."
Alternatives: "and hard to incorporate" or "and challenging to add".
The focus on migrant patients, who are often socioeconomically disadvantaged and more difficult to include in studies, made this approach reasonable.
The first is that some important process variables (e.g. PRESS PRESSURE) are not categorical variables and therefore more difficult to include as independent variables.
Furthermore, in the COI method, it is difficult to consider the quality of life of the patients, and it is also difficult to include a change of utility and efficiency of a specific treatment into analysis.
However, knowledge on the private sector providers is limited and this makes it difficult to include them in health care planning.
They account for many significant factors such as arbitrary geometries, nonhomogeneities in material composition, complex boundary conditions, nonlinear material behavior (constitutive modeling) and complex loading conditions, which were difficult to include in conventional and closed form solution procedures.
Given these and associated problems, it was difficult to include institutional features directly in our econometric analysis.
The study was based on chart revision where incomplete documentation, inappropriate chart labeling and lost records made it difficult to include all patients registered for dialysis.
This variety in their background before placement and after placement makes it difficult to include every relevant variable in quantitative analysis.
In a medical setting, the cost items that are directly associated to the intervention are more or less easy to determine; indirect cost and long-term costs consequences of a chronic disease state or of its avoidance are more difficult to include and will often be based on estimations.
81 However, a concern with taxing a wide range of products would be the fact that people should be encouraged to consume a wide range of food and beverage products, eg, milk and olive oil, that would be difficult to include in the tax category.
