The phrase "additive index" is correct and usable in written English.
It can be used in contexts related to mathematics, statistics, or data analysis where an index is constructed by adding values together.
Example: "The additive index allows researchers to quantify the cumulative effects of various factors on the outcome."
Alternatives: "cumulative index" or "summative index".
Based on these individual questions an additive index was created, representing the overall public support for renewable energy policies.
This is an additive index of three questions asking respondents their opinion about how efficacious they consider their governments are in fighting poverty, unemployment, and insecurity (efficacy).
Community participation is an additive index of four questions, asking respondents how often they attend meetings organized by religious groups, parents' associations, neighborhood organizations, and women's groups.
In general, weighted index SQIs were better correlated with crop yield than the additive index SQIs for both PCA and EO methods.
Finally an additive index KBS was constructed by combining OHK, OHB and OHS scores.
The response variable was created as an additive index (including positive entries only).
An additive index was constructed on the basis of the SRQ-10, and respondents with 'yes' on 3 or more of the questions were classified as mentally distressed.
Parental SES was defined in three categories using an additive index based on maternal and paternal educational background and current type of maternal and paternal employment [ 18].
We found no association between the children's total problems and their fathers' trauma variables, neither single variables nor the additive index for extreme trauma.
Using the BIC and Raftery's (1995) statistical criteria for goodness-of-fit model comparison, there was positive evidence that model 2 (HVI factor scores) is preferred over model 1 (HVI additive index score).
