Apdex Score

Apdex is a measure of response time based against a set threshold. It measures the ratio of satisfactory response times to unsatisfactory response times.

The response time is measured from an asset request to completed delivery back to the requestor.

It determines user satisfaction, and is based on request type & response time.

All what You need are two fields: _time and Response time.

For datamodels:

| tstats values(response_time) as response_time from datamodel=<datamodel_name> where nodename=<node> by Main.response_time, _time span=1s 
| eventstats p90(response_time) as threshold by _time 
| eval request_type = case(response_time<=threshold, "satisfied", 
    response_time>threshold AND response_time< threshold*4, "tolerating",
    response_time>=threshold*4, "frustated") 
| timechart count as num by request_type 
| addtotals label=total col=f row=t 
| eval apdex = (satisfied+(tolerating/2))/Total 
| fields _time, apdex

For indexes:

index=<index_name> 
| fields _time, response_time
| eventstats p90(response_time) as threshold by _time 
| eval request_type = case(response_time<=threshold, "satisfied", 
    response_time>threshold AND response_time< threshold*4, "tolerating",
    response_time>=threshold*4, "frustated") 
| timechart count as num by request_type 
| addtotals label=total col=f row=t 
| eval apdex = (satisfied+(tolerating/2))/Total 
| fields _time, apdex

It is pretty easy to understand, so feel free to use it.

Hope you find it useful!