Calculating PozQoL scores
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Process for using PozQoL
IMPORTANT: PozQoL should only be used with people living with HIV (PLHIV).
📚 Related resource: PozQoL Implementation Kit (pdf download)
Calculating PozQoL scores
Calculating PozQoL scores is a 2-part process:
- Code items — Ensures that for all items, higher scores indicate higher quality of life (QoL)
- Calculate the scores — Produces scores for each QoL domain and a score for overall QoL
The information on this page explains how to do this manually.
The PozQoL team has also developed tools to do this for you.
Part 1: Coding PozQoL Items
Coding is when you take your client’s responses to the PozQoL scale and give them a number value that you can use for calculations.
When someone completes PozQoL, they indicate how strongly they agree with a statement on a scale from 1 (not at all) to 5 (extremely).
Some of the items indicate positive feelings; for example, “I am enjoying life”. Agreeing with this statement is an indication good quality of life. So, a response of 4 or 5 would indicate good quality of life.
Other items indicate negative feelings; for example, “I worry about my health”. Agreeing with this statement might indicate poor quality of life. So, a response of 4 or 5 would indicate a poor quality of life.
To calculate PozQoL scores, we need to “code” responses in such a way that higher numbers always indicate better quality of life.
The following steps illustrate how this is done.
Start with a completed PozQoL Scale
Here is an example of a completed PozQoL Scale.
The response options for each item are:
- Not at all
These numbered responses are used to score the scale.
Code the positively worded items
Four (4) items are positively worded. These are Items 1, 5, 8, and 13.
The coding for positively answered items is the same as the response numbers:
- Not at all = 1
- Slightly = 2
- Moderately = 3
- Very = 4
- Extremely = 5
Code the negatively worded items
Nine (9) items are negatively worded. These are Items 2, 3, 4, 6, 7, 9, 10, 11, and 12.
The coding for negatively answered items is the reverse of the response numbers:
- Not at all = 5
- Slightly = 4
- Moderately = 3
- Very = 2
- Extremely = 1
Part 2: Calculating the PozQoL Scores
PozQoL Scores can be calculated for overall quality of life (PozQoL score), and for each domain (PozQoL domain scores).
The following table details which items are used to calculate each type of score.
|Scale||Number of items||Items to score|
|PozQoL score (overall QoL)||13||All (1 – 13)|
|Psychological domain||4||1, 5, 8, 13|
|Social domain||3||3, 9, 11|
|Health concerns domain||3||2, 7, 12|
|Functional domain||3||4, 6, 10|
Scores can be calculated either as an average or as a sum. Average scores are preferable, but summary scores are easier to calculate manually.
Calculating average PozQoL and PozQoL domain scores
Average scores are preferred because they are valid even if some items are left blank. That said, we do not recommend calculating average scores for specific domains if more than one item from that domain is blank.
To calculate the PozQoL score, find the average of the scores from all 13 items.
To calculate the PozQoL domain scores, find the average the scores of each domain’s items.
Scores can range from 1 to 5.
Remember, we do not recommend calculating average PozQoL domain scores if more than one item is left blank.
Calculating Summary PozQoL and PozQoL Domain Scores
Summary scores are easier to calculate when administering PozQoL as a pen-and-pencil copy in one-on-one consultations. However, summary scores are only valid if all items are answered.
Add the scores from all 13 items to find the overall quality of life score. Add the scores of each domain’s items to find the domain scores. Higher scores indicate better quality of life.
- PozQoL (overall quality of life) score can range from 13 to 65
- Psychological domain scores can range from 4 to 20
- All other domain scores can range from 3 to 15
Remember, summary scores are only meaningful when all of the relevant items have been answered.
The following example uses the coded scores we worked out previously to calculate our example client’s PozQoL Scores.
Their coded PozQoL scale is shown here. The colours indicate which item belongs to each domain.
- Psychological domain items (blue) include items 1, 5, 8, and 13.
- Social domain items (red) include items 3, 9, and 11.
- Health concerns domain items (green) include items 2, 7, and 12.
- Functional domain items (yellow) include items 4, 6, and 10.
Because this client did not leave any items blank, we can use whichever method is easiest to for calculating their PozQoL scores.
Their PozQoL scores are:
|PozQoL Score Type||Summary Score||Average Score|
|Health Concerns Domain||9||3.00|
|PozQoL Score (Overall)||48||3.69|
The information below shows in detail how these scores were calculated.
Calculating domain scores
Using the same scores that we coded earlier, we see here that the scores for the items the different domains.
Psychological domain scores
The scores for the four (4) items in the psychological domain are 4, 5, 4, and 3.
The sum of these scores is 16 and the average is 4.00.
Therefore, this client’s psychological domain scores are:
- Summary score = 16
- Average score = 4.00
Social domain scores
The scores for the three (3) items in the social domain are 5, 3, and 4.
The sum of these scores is 12, and the average is 4.00.
Therefore, this client’s social domain scores are:
- Summary score = 12
- Average score = 4.00
Health concerns domain scores
The client’s scores for the three (3) items in the health concerns domain are 3, 4, and 2.
The sum of these scores is 9 and the average is 3.00.
Therefore this client’s health concerns domain scores are:
- Summary score = 9
- Average score = 3.00
Functional domain scores
The client’s scores for the three (3) items in the functional domain are 3, 3, and 5.
The sum of these scores is 11, and the average is 3.67.
Therefore, this client’s functional domain scores are:
- Summary score = 11
- Average score = 3.67
Calculating the overall PozQoL score
The sum of the scores for all 13 items is 48.
We get this from adding all 13 scores together.
The average of these scores is their sum (48) divided by the total number of items (13), which is 3.69.
Therefore, this client’s overall PozQoL score are:
- Summary score = 48
- Average score = 3.69