This study was conducted using a unique maternal population: urban, multi-ethnic and with a high degree of deprivation.
Formal certification appears to be used on a unique population of patients (involuntary) who require treatment and differ substantially from patients without formal status (voluntary).
The Swedish Medical Birth Registry is linked to several other national databases, including the National Inpatient Registry, the National Mortality Registry, the Swedish Drug Prescription Register, the Register of the Total Population and the Swedish 1990 population census, using a unique personal identification number (PIN).
The medical records were matched to individual records in the Dutch population registry using a unique anonymous patients' identifier (based on gender, date of birth, and postal code).
Our vignette-adjusted measure of risk aversion is tested using a unique tailor-made representative survey of the migrant population in Greater Dublin, Ireland, conducted by the authors.
15 This centre enables anonymised linkage of health records from the population of Tayside (400 000), Scotland, using a unique identifying community health index number.
Our access to high-quality population-based medical databases, linked using a unique personal identifier, may explain the good overall performance of the administrative data in our study.
Nurses were tracked using a unique identifier.
First, we used a unique study population based on the Health 2000 Study and supplemented with military service records of all men aged 30 50 years.
For this purpose, we used a unique resource population (SEGFAM) which had been established for the examination of the background for divergent muscle protein accretion in cattle [ 26].
