Statistical Considerations

The study is descriptive in nature and as such descriptive statistics shall be utilised to analyse the data. Distributions of variables will be presented with histograms and/or frequency tables. Medians or means will be used as the measures of central location for ordinal and continuous responses and standard deviations and quartiles as indicators of spread. Categorical and binary data will be presented using frequency tables and proportions. Appropriate 95% confidence intervals will be presented for all descriptive statistics. Analyses of the objectives will include the use of the following inferential statistical techniques:

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with FW flight times, a T-test or Mann-Whitney test shall be utilised.  For the comparison of continuous variables, such as the reporting the

differences between age groups or differences between diagnostic, an analysis of variance (ANOVA) – post hoc test shall be utilised.

 For the comparison of categorical variables, such as the time intervals between RW and FW flights, a Chi2 _{test shall be used.}

Those variables and tests for which the assumption of normality is required will be tested for normality and if found to be deviating from normal they will be analysed using the appropriate non-parametric tests. A significance level of 5% will be applied to all analyses. A p-value of p < 0.05 will represent statistical significance in hypothesis testing and 95% confidence intervals will be used to describe the estimation of unknown parameters.

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3. - Ethics

 This study complies with the 2008 revision of the Declaration of Helsinki.  Only anonymised data will be used for the study. Any identification

information shall be documented separately and only be utilised for data capturing purposes.

 Ethical approval for the study will be applied for via the University of Cape Town.

 Permission to access the patient records and aviation flight logs has been applied for and approved by the AMS Research Committee (See Section 7: Annexure 5). AMS has been given the contact details of the supervisors should any grievances with the research student arise at any time during the study.

 A waiver of informed consent is requested due to: - The study is a low risk descriptive analysis.

- The study is retrospective, examining a period of 3 years. Informed consent will significantly add to the timeframe and workload of the study overall.

- No identifiable patient data will be recorded during any phase of the study. In addition, all information captured during the study shall be securely stored by the research student on three password protected external USB storage devices and an online storage site.. Access to this information shall only be made available to the study supervisors.

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4. – Limitations

 The study is retrospective in nature and as such is constrained by the limitations of this study design. This design is limited by the reliability of the source material as well as the ability to predefine parameters or end points to be measured. As a result of this, the study will be limited in the conclusions that can be drawn, and as such is confined to a descriptive nature.

 There is only one data capturer, the research student, who will not be blinded to the study details and objectives.

 There will be no supervision of the data collection process. However, the data will be separately transcribed onto two data capture templates, to be continually compared on a weekly basis throughout the data collection process. This will be done to avoid transcription errors and to ensure the data is transcribed correctly and in its entirety.

 The data collection is confined to the Cape Town Base only and does not include data from other bases of the RCAMS across the country.  Due to the retrospective nature of the study, there is the possibility of

missing, incomplete or illegible patient report forms and aviation flight logs. This has potential to impact the results of the final analysis.  RCAMS is the official air medical service provider of the Western Cape

Provincial Department of Health and as such, data from this service represents the population who utilise the provincial health services. While the RCAMS does also transport patients utilising private health care facilities, the RCAMS is not the only service provider offering this service to this population. The study does not take into account the data of private air medical service providers.

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5. – Timeline

Following ethical approval, the study will be completed for final submission in 5 months. Month Activity 1 - Data collection 2 - Data collection - Statistical analysis 3 - Statistical analysis - Write up of 1st draft

- Submission of 1st draft to supervisor

4 - Feedback and corrections

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6. – Resources and Budget 6.1 – Resources

Description Source

Statistical services - Centre for Statistical Consultation, Stellenbosch University

Telephone & cellular

communication - Research student

Internet access & email

facilities - Research student

Computer access & data

storage - Research student

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6.2 – Budget

Item Description Unit cost No. units Sub-total

Statistical analysis Analysis of data for final write up R 185.00 5 R 925.00

Communication Telephone & cellular R 500.00

Internet access and

email facilities R 500.00

Computer access and

data storage External USB storage device R 500.00 3 R 1500.00

Printing & copying R 0.30/pg. 300 R 900.00

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of Cape

Town