This study will investigate the cost and impact of Healthcare Associated Infection (HAI) to patients, the health service and the wider community.

This is in order to develop a model to allow policy makers to compare the cost effectiveness of Infection Prevention and Control measures in NHSScotland. The model will support policy makers and clinical teams in building a patient centred, safe, effective and efficient service.

Healthcare associated infection (HAI) also known as Nosocomial Infection (NI) is costly to the NHS and distressing to patients. It leads to increased morbidity and mortality, increased length of stay and often requires additional treatments. Information on the impact in terms of additional cost of treatment, reduction in quality of life and cost to society is not fully described. This study will collect epidemiological and economic data on patients with and without HAI and develop a framework around which the cost effectiveness of a range of Infection Prevention and Control (IPC) interventions can be assessed.

The study will be delivered as 4 distinct but overlapping work Phases Phase 1 will describe the incidence of HAI (defined by ECDC case definitions) in an admission cohort. This phase is a surveillance project.

Phase 2: Will describe the impact of HAI on care in hospital -as many patients as possible who acquired HAI and twice as many non-HAI comparators will be recruited. Patients or their guardians or nearest relative will be told about the study and asked if they are willing to provide consent to complete a number of questionnaires. This phase will include case note review by ECONI research nurses and a patient questionnaire.

Phase 3: Will investigate the impact of HAI on patient care post discharge (use of Health and Social Care resources outside of Hospital), Quality of Life and personal expenses) - questionnaire to patients to ask about impact on their overall health and wellbeing and personal expenses. This will involve patients completing a paper questionnaire at one, three, six and twelve months after they have been discharged from hospital. This phase will include a nested qualitative study which will interview 20-30 patients who acquired HAI to further investigate the impact of HAI on their lives and livelihoods Phase 4: This phase will not involve any patient interaction. It will develop a framework to support modelling for decision making for future investment in Infection Prevention and Control (IPC) based on data collected within Phase one to three above. The information collected during the first three phases will be used to model possible outcomes of infection prevention and control measures. This will be a modelling exercise using data collected within Phase 1, 2 and 3 and the protocol for this work will be described elsewhere.

Phase 2 and 3 will be a cohort of as many patients as possible with HAI and a sample of non-HAI patients (twice the number of HAI patients) who consent to participate in the study within the year of recruitment.

Modes of data collection

1. Research Nurse administered questionnaire on recruitment quality of life questionnaire on recruitment
2. Day before discharge quality of life questionnaire
3. 1 month post discharge questionnaire
4. 3 month post discharge questionnaire
5. 6 month post discharge questionnaire
6. 12 month post discharge questionnaire
7. Record linkage - SMOR00, SMR01, PRISMA, District nursing
8. 1,500-3,000 patients recruited for follow up.
9. All admissions to study hospitals for record linkage. Follow up duration 1 year post discharge from admission when patient was recruited.

Data will be collected using a Redcap database. Where possible controlled lists will be included within the database to ensure consistency of reporting. Validation visits to study sites will be undertaken throughout the study data collection period. Standard operating procedures will be developed for the ECONI team to use during recruitment and data collection. A data dictionary will be developed to record all data items recorded during the study, where these data were sourced, the choices available and the field-names within the data set. A publications and communication plan has been developed for the study and an analysis plan will be developed linking each of the objectives to a peer reviewed publication. A number of systematic reviews have be undertaken in the development of the ECONI study protocol.

Inclusion Criteria:

1. Admitted to hospital for an overnight stay at study hospital
2. Subjects capable of giving informed consent, or if appropriate, subjects having an acceptable individual capable of giving consent on the subject's behalf
3. Any sex
4. 18 years old and over
5. Patients without HAI will not be re-recruited into the study. Patients who have HAI on a subsequent admission will not be re-recruited but will be asked to complete a baseline data collection form (see below for discussion) NOTE: we do need to ensure this is clear within the ethics application.
6. Good English language skills (sufficient to read and understand the participant information sheet without help)

Exclusion Criteria:

1. Admitted to hospital as a day case
2. Admitted to Hospitals other than the study hospitals
3. Under 18 years
4. Admitted to the study hospital during the study period and recruited to the study during a previous stay. See below
5. Subjects not capable of giving informed consent unless legal representative or relative can provide proxy consent
6. Patients who do not have English language skills to read and understand the information sheet without help

Adult patients admitted to study hospitals over night during a one year study period

The study Steering Committee will review this at the end of the study. Data will be only be shared at an individual level if all identifiable information has been removed or categorised, individual records would be identified using a cypher code.