Trusted Data Linkage Service

Trusted Data linkage Service

Data

• HES, PROMS, ONS, MHMDS, Cancer

Customers• Universities, NHS, research, government, commercial

• DCLG – Homelessness

• The Nuffield Trust – Person based resource allocation

• Dept. for Transport – STATS19

• IMS – Hospital prescribing data

• GPRD, CSDMR, QResearch – GP data linkage

• Fields used:• NHS number• Date of birth• Sex• Postcode• (Names)

Linkage algorithms

NHS DoB Sex Postcode1 Exact Exact Exact Exact2 Exact Exact Exact3 Exact Partial Exact Exact4 Exact Partial Exact5 Exact Exact

6 Exact Exact ExactWhere NHS doesn't contradict the match, DoB not 1st Jan & postcode not in ignore list

7 Exact Exact ExactWhere NHS doesn't contradict the match, DoB not 1st Jan

8 Exact Exact Exact Where DoB not 1st Jan

Probabilistic• Very processor intensive – HESID index availability• Expensive• Useful when things are similar

• NHS numbers are exact

Deterministic• Efficient• Cheaper• Less accurate?• Algorithm accounts for most common keying error

Deterministic vs. probabilistic