BSPS 2008 1General Register Office
forS C O T L A N D
information about Scotland's people
Review of migration methods using health registrations
Nick Wright
Cecilia Macintyre
General Register Office for Scotland
BSPS 2008 2General Register Office
forS C O T L A N D
information about Scotland's people
Overview of Presentation
• Description of method of estimating migration for areas in Scotland
• Comparison of NHSCR and CHI estimates
• Developments in sources
• Future work
BSPS 2008 3General Register Office
forS C O T L A N D
information about Scotland's people
Sources of data used in internal migration
• NHSCR Movements are recorded between Health Board Areas and UK countries
• CHI movements allow migration to be measured below health board area
BSPS 2008 4General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR
• Originally set up in 1939 for purpose of call-up for military service and food rationing
• Function - to maintain a register of all NHS patients on lists of general practitioners in Scotland
• To supply info to organisations in health service and for medical research
BSPS 2008 5General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR
• Currently holds records for every patient registered, now or in the past with a Scottish GP
• Everyone born in Scotland since 1985 who have not been registered with a Scottish GP
• Patients formerly registered with a Scottish GP, who died after 1992
BSPS 2008 6General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR dataset
• Unique NHS number
• Unique Community Health Index number
• Names
• Date of birth
• Current and previous registrations with UK health authority
• Medical flags
BSPS 2008 7General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR migration data
• Monthly files provide individual records for all changes in posting with age and sex– Scottish Health Board– England & Wales Health area – Northern Ireland – Armed Forces – Immigrants and embarkations
BSPS 2008 8General Register Office
forS C O T L A N D
information about Scotland's people
Community Health Index
• All patients registered with a GP in Scotland, or those in contact with health service allocated CHI number
• Since 1997 there has been a unique CHI number allocated
• Aim to use throughout health service for identification
BSPS 2008 9General Register Office
forS C O T L A N D
information about Scotland's people
CHI annual extract
• Information includes– CHI identifier (anonymised )– Current status– Age/sex– Health board of residence + Postcode– Transfer in/out dates + Area codes – Immigrant code
BSPS 2008 10General Register Office
forS C O T L A N D
information about Scotland's people
CHI processing(1)
• CHI extract (1) – Select currently registered patients
• CHI extract (2)– Select currently registered patients and those
‘leaving’ within last year
BSPS 2008 11General Register Office
forS C O T L A N D
information about Scotland's people
CHI processing(2)
• Match two extracts using unique CHI– Current patients in both extracts – Current patient in extract 1 but not in extract 2 – Current patient in extract 2 but not in extract 1
Use information on postcodes and postings to allocate migration at lower level
BSPS 2008 12General Register Office
forS C O T L A N D
information about Scotland's people
Research questions
• Require to understand relationship between two sources
• NHSCR will be extended to include postcode updates from CHI, proving a new single source
• Understand impact of changes in methods
BSPS 2008 13General Register Office
forS C O T L A N D
information about Scotland's people
Comparison of Migrants within Scotland (Male)
0
500
1,000
1,500
2,000
2,500
Age
Males, NHSCR Males, CHI
BSPS 2008 14General Register Office
forS C O T L A N D
information about Scotland's people
Comparison of RUK Migrants out from Scotland (Male)
0
100
200
300
400
500
600
700
800
900
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Age
Males, NHSCR Males, CHI
BSPS 2008 15General Register Office
forS C O T L A N D
information about Scotland's people
Comparison of RUK Migrants into Scotland (Male)
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Age
Males, NHSCR Males, CHI
BSPS 2008 16General Register Office
forS C O T L A N D
information about Scotland's people
Comparison of RUK Migrants into Scotland (Female)
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Age
Females, NHSCR Females, CHI
BSPS 2008 17General Register Office
forS C O T L A N D
information about Scotland's people
Comparison of Overseas Migrants into Scotland (Male)
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Age
Males, NHSCR Males, CHI
BSPS 2008 18General Register Office
forS C O T L A N D
information about Scotland's people
Absolute Comparison of CHI vs NHSCR Migrants to the Rest of the UK
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
Argyll
& C
lyde
Ayrsh
ire &
Arra
n
Borde
rs
Dumfri
es & G
allow
ay Fife
Forth
Val
ley
Gra
mpia
n
Gre
ater G
lasg
ow
Highla
nd
Lana
rksh
ire
Loth
ian
Ork
ney
Islan
ds
Shetla
nd Is
land
s
Taysid
e
Weste
rn Is
les
Health Boards
Mig
ran
ts t
o R
UK
0%
20%
40%
60%
80%
100%
120%
140%
CH
I as
%ag
e o
f E
WM
IG
2007 CHI 2007 NHSCR CHI as %age of NHSCR
BSPS 2008 19General Register Office
forS C O T L A N D
information about Scotland's people
Absolute Comparison of CHI vs NHSCR migrants from the Rest of the UK
0
2,000
4,000
6,000
8,000
10,000
12,000
Argyll
& C
lyde
Ayrsh
ire &
Arra
n
Borde
rs
Dumfri
es & G
allow
ay Fife
Forth
Val
ley
Gra
mpia
n
Gre
ater G
lasg
ow
Highla
nd
Lana
rksh
ire
Loth
ian
Ork
ney
Islan
ds
Shetla
nd Is
land
s
Taysid
e
Weste
rn Is
les
Health Boards
Mig
ran
ts f
rom
RU
K
0%
20%
40%
60%
80%
100%
120%
140%
CH
I as
%ag
e o
f S
MIG
2007 CHI 2007 NHSCR CHI as % of NHSCR
BSPS 2008 20General Register Office
forS C O T L A N D
information about Scotland's people
Issues to consider in understanding patterns
• Differences in what is being measured– Counts of events (NHSCR)– Change in status one year apart
• Exclusion of some situations e.g. cancelled records
• Impact of multiple movements within a year
BSPS 2008 21General Register Office
forS C O T L A N D
information about Scotland's people
Patterns of short term cross-border migration
• Current approach of identifying in migrants on CHI will undercount total because of moves within year
• Identified new patients on second CHI extract who had moved within the year
BSPS 2008 22General Register Office
forS C O T L A N D
information about Scotland's people
Distributions of STM Migrants moving between RUK to Scotland In Under a Year
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
6.0%
7.0%
8.0%
9.0%
10.0%
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Age
% o
f T
ota
l
Females Males
BSPS 2008 23General Register Office
forS C O T L A N D
information about Scotland's people
So what?
• Current allocation of in-migrants to Scotland from Rest of UK will use distribution of migrants who do not move subsequently
• Require to compare this with the destinations of people to move more frequently
BSPS 2008 24General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR extract development
• Transfer of Scottish NHSCR system has provided opportunities
– Additional fields on database
– Additional capability for analysis
BSPS 2008 25General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR extract (2)
• New fields on database will include
– Postcode (updated through CHI system)
– Country of Birth
BSPS 2008 26General Register Office
forS C O T L A N D
information about Scotland's people
NHSCR extract (3)
• Additional capability for analysis– Project underway to receive monthly extract
from NHSCR system– Details of all people on system – Complete history of postings– Complete history of postcode from 2008
onwards
BSPS 2008 27General Register Office
forS C O T L A N D
information about Scotland's people
Thank you
Questions?