Study design and participants
STEPwise approach to stroke surveillance.
Resultados Censo 2017. Web Diseminación Censo.
This region is low income, with 16·1% living below the poverty line according to income compared with the national average of 8·6%. As for most of the country, health care in the region is mainly provided by the public health system, 80% of the population being affiliated to this health system. At the time of this study, the regional public hospital system included one large 470 bed general hospital with continuous CT scan availability and a dedicated stroke unit; one medium-size 116 bed hospital with continuous CT scan availability and a preferred stroke unit; and five small community hospitals of less than 100 beds each. There were four community family health centres, two outpatient clinics, and six walk-in ambulatory-only emergency clinics. Additionally, one small private hospital of 46 beds with continuous CT and MRI was available. There were 517 doctors in the region, many of whom had afternoon private practices.
We prospectively screened multiple overlapping sources for possible stroke cases. We checked emergency consultations, hospital admissions, and discharge diagnosis lists each day in each hospital in the region. Weekly checks were also done on discharge diagnosis lists from hospitals in the large nearby Concepción province in case any patients with a known residence in Ñuble had been admitted. Weekly checks were also done of intensive or intermediate care units, internal medicine, and other relevant medical wards, as well as outpatient clinics, CT scans, and carotid duplex orders in the two larger hospitals in the region (within a specified timeframe of days of weeks [hot pursuit]). Monthly checks of all hospital discharges in Ñuble during the study period were also done with use of the National Statistic Hospital Discharge Registry system to identify cases based on categories I60–I69 and G45 of the International Classification of Diseases (ICD), tenth revision (over a longer timeframe [cold pursuit]).
We also did weekly checks of all death certificates of residents in the Ñuble region through the national death registry to identify individuals who were not admitted to hospital. We included all ICD-10 I60 to I69 codes as primary diagnoses, and reviewed all other diagnoses in the death certificate, including all those with an incident stroke. We excluded cases who died because of a stroke occurring before the study period. We cross-checked all individuals who had a stroke and died with the national discharge registry database from 2010 to 2016 to ensure identification of first-ever strokes. We prevented double-counting by identifying cases with their national identification number in the screening log.
Patients were ascertained from April 1, 2015, to March 30, 2016. Follow-up continued until March 30, 2017, for the last patient identified. Because of the large size and geographical extension of the population studied, budget constraints only allowed us to perform the study for 12 months, with another 12 months’ follow-up.
To ensure referral of all possible patients who had a stroke occurring during the study period, we sent letters and emails to local physicians, held meetings with private health centres, and together with the local health service organised a monthly stroke seminar held at the public general hospital (Herminda Martin Clinical Hospital of Chillán) from 2014 to 2016, open to primary care, emergency, inpatient, and ambulatory care personnel of the public health sector in the region, as well as the students and faculty of the universities who worked in the local health sector. This meeting was not mandatory, but all personnel and students could attend the meetings in their working hours.
A public stroke prevention and symptom recognition awareness campaign was also launched during the study period, including flyers, newspapers, and local television interviews and World Stroke Day activities in Chillán, the regional capital city. Social networks were used too, including a project webpage and a Facebook page, providing information about the study, a dedicated contact telephone number and email for referrals, and stroke care and prevention tips for physicians, health personnel, local authorities, and the general public. We also organised a stroke awareness and prevention programme with workers from one of the largest food industries in the region. Regular meetings with the hospital directors and local health authorities were held before and throughout the study period to inform them about the project and to organise the transfer of all local important administrative data regarding stroke cases. Similarly, we lectured about stroke epidemiology and care in local university meetings during the study period.
All cases identified as possible strokes were reviewed by the field investigator (AMM) and one of two trained study nurses (CG, DSM) and, if confirmed according to the study definitions, were contacted to obtain informed consent directly or from their next of kin. Study data were collected and managed using REDCap electronic data capture tools hosted at Universidad Mayor. Once consent was obtained, the study nurses extracted all the relevant medical and imaging information and registered it on an online electronic case report form in the RECap platform. Doubtful or difficult cases were discussed with one of the field neurologists (AV, AR, or EL).
- Williams LS
- Yilmaz EY
- Lopez-Yunez AM
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- Lindsell CJ
- Alwell K
- Moomaw CJ
- et al.
Severity of intracerebral haemorrhage, subarachnoid haemorrhage, cerebral sinus venous thrombosis, and undetermined stroke type is described according to the admission Glasgow Coma scale scores.
We extracted data for and recorded all relevant clinical, neuroradiological, radiological, cardiac, and laboratory tests, as well as management and outcomes that were recorded in the patient clinical notes. No tests or examinations were done beyond usual clinical practice. Causes of death were divided into neurological, infectious, cardiovascular, cancer, and other.
Patients were followed up at 1, 6, and 12 months after the stroke by trained personnel who undertook a telephone interview with the patient, their next of kin, or caregiver with a standard questionnaire. This interview was requested in patients who were known to be alive. To ensure that we did not call patients who had died or their family members or caregivers, we checked death certificates weekly for all ascertained cases during the study period. Information about recovery, dependency, health-related quality of life, dwelling, secondary prevention medications, use of health-care and rehabilitation facilities, stroke recurrence, and cost was obtained in all followed-up cases.
The study was approved by the scientific ethics committee of the Universidad del Desarrollo, Clínica Alemana School of Medicine in Santiago, and the local scientific ethics committee of the Herminda Martin Clinical Hospital in Chillán, Ñuble region. According to the local ethics committee decision, written informed consent was obtained in all cases included in the analysis, except those identified through death certificates.
We calculated crude incidence rates using the 2017 national Census data projection for 2015. Incidence rates for first-ever strokes were age-adjusted to Chilean, European, and world populations by the direct method.
