The survey can be administered to all staff (a census), a proportion of all staff (a representative sample), or focus on specific units or staff positions (a targeted sample).
Census
A census approach has the following advantages and, where resources are available, is the preferred option for most hospitals as it:
- Conveys a message of inclusiveness by giving all staff the opportunity to provide feedback
- Results in data that are more representative of your hospital’s workforce
- Allows for more detailed analysis and reporting of results at a unit and department level
- Makes communication about the project easier.
Targeted sample
A safety culture measurement project may be focused on specific groups within the hospital. This may be due to resource constraints or to examine an issue that has been identified through other means. You may focus on:
- All staff from a number of units/work areas/ departments
- All staff within specific positions or levels of experience
- A combination of the above.
This approach should never involve purposeful selection of individuals from within these groups.
A targeted approach can have the following challenges that will need to be managed through careful communication and engagement:
- Concerns about why a the focus is on a particular group
- Clarity about who is included in the sample.
Additional care also needs to be taken to ensure that the data is reported in a way that protects the confidentiality of respondents (See the technical specifications for the A-HSOPS 2.0).
Representative sample
Using a representative sample is a way of decreasing the resources required to measure patient safety culture which can be useful in large hospitals.
You can expect to receive completed surveys from about 30 to 50 percent of the sample. The table below shows the recommended minimum sample sizes using a 50 percent response rate. You should update the estimated response rate based on your previous experiences with staff surveys to calculate your sample. The more staff surveyed, the more likely you are to have a representative sample.
Number of staff |
Recommended sample size |
Number of surveys to send out (based on 50% response rate) |
500 (or fewer) |
250 (or fewer) |
500 - a census of all staff |
501-699 |
250 |
500 |
700-1,299 |
300 |
600 |
1,300-3,999 |
350 |
700 |
4,000 or more |
375 |
750 |
It is important to use a method that ensures the sample is representative – staff should never be purposefully selected to complete the survey. Options for sampling include:
- Simple random sampling: involves selecting staff randomly so that each staff member has an equal chance of being selected
- Systematic sampling: involves selecting every Nth person from a staff list. To begin, sort your staff list by unit/work area and then by staff position. If you have a list of 1,200 names and need to select 600 to include in your sample, you begin at a random point on the list and then select every other name on your list. Thus, if you begin with the first person on the list, you select the 2nd, 4th, 6th, 8th, etc., staff member, compiling a total of 600 names in your sample.