Narrative review of neurology studies (2020–2025) using the German IQVIA Disease Analyzer highlighting outpatient diagnoses, prescribing patterns, and methodological strengths and limitations across disorders including Parkinson’s disease.

Provides useful real-world epidemiology and treatment-pattern context for Parkinson’s but offers minimal mechanistic, biomarker, or intervention insights needed for direct therapeutic discovery, so it mainly guides study design and complementary data needs.

BACKGROUND: The IQVIA Disease Analyzer (DA) database is a major outpatient electronic health record dataset in Germany. Over recent years, it has been increasingly used to study neurological diseases, comorbidities, treatment patterns, and long-term sequelae. We narratively summarized neurology-related studies using the German IQVIA Disease Analyzer (DA) database published since 2020 and to highlight methodological considerations relevant for interpreting DA-based neurological research. METHODS: We conducted a narrative review of DA-based studies published between January 2020 and December 2025. PubMed was searched using DA-related keywords and major neurological disease terms. Eligible articles included peer-reviewed cohort, case-control, or descriptive studies using DA outpatient data. RESULTS: The review identified studies covering epilepsy, cerebrovascular outcomes, Parkinson's disease, dementia, multiple sclerosis, migraine, and sensory disorders. Most used retrospective cohort or nested case-control designs with regression or propensity score methods. Follow-up durations ranged from 3 to 10 years. Results consistently reflected routine care outpatient diagnostic and prescribing patterns. DISCUSSION: Strengths of DA studies include large patient populations, long follow-up, and detailed prescription information. Limitations include reliance on outpatient ICD-10 coding, lack of detailed neurological phenotyping, and potential residual confounding and bias. CONCLUSIONS: DA-based analyses generate clinically relevant routine care evidence on neurological conditions in the German outpatient setting. Proper methodological safeguards and complementary data sources are required to contextualize findings for clinical and epidemiological use.