The phrase "a practical index of" is correct and usable in written English.
It can be used when referring to a measurable or observable indicator that provides useful information about a particular subject or concept.
Example: "The survey results serve as a practical index of customer satisfaction within our service."
Alternatives: "a useful measure of" or "a reliable gauge of".
We developed a practical index for capturing health service coverage – a critical dimension of UHC -- that was more inclusive than previous methods.
Therefore, more "practical" indices of fit were used to evaluate each model's fit as well as to compare alternative models, according to the recommended cut-offs [ 33, 34].
This is a more practical index for assessing severity of pneumonia illness at presentation because it is easy and quick to assess the severity, where blood urea measurement is omitted from the CURB-65 scale [ 24].
On the other hand, waist circumference (WC), a more direct measure of the abdominal accumulation of fat [ 15], and waist-to-height ratio (WHR), a more practical index for screening the risk of obesity-related disorders that could be applied uniformly to all ethnicities and ages [ 16], are also important and reliable obesity indexes [ 16- 18].
Based on questionnaires presented before (N = 197) and after (N = 147) the intervention, an eating acceptance index expressing eating qualities and a practical acceptance index expressing practical implications of the diet in everyday life were developed.
Defining a mean and uncertainty interval for the AFR index of each chemical being ranked provides a practical method of incorporating data uncertainty into a regulatory protocol.
Higher social support measured as a single index of emotional, financial and practical support was associated with a higher likelihood of meeting physical activity guidelines in working-class multi-ethnic adults.
A Practical Handbook of Polite Drinking".
There's a practical reason, of course.
There may be an important, and difficult, practical dilemma to develop an index of entomological population change that integrates complex ecological traits and can identify conservation problems.
