Angus D Macleod1, Rachel Henery2, Paul C Nwajiugo3, Nicholas W Scott4, Robert Caslake5, Carl E Counsell6. 1. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK. Electronic address: angus.macleod@abdn.ac.uk. 2. Aberdeen Royal Infirmary, Aberdeen, UK. Electronic address: rachel.henery@nhs.net. 3. Freeman Hospital, Newcastle upon Tyne, UK. Electronic address: paul.nwajiugo.14@aberdeen.ac.uk. 4. Queen Elizabeth University Hospital, Glasgow, UK. Electronic address: nicholas.scott3@nhs.net. 5. Aberdeen Royal Infirmary, Aberdeen, UK. Electronic address: rcaslake@nhs.net. 6. Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK. Electronic address: Carl.Counsell@abdn.ac.uk.
Abstract
OBJECTIVE: To describe, and explore heterogeneity in, age at onset/diagnosis in Parkinson's disease (PD) and compare mean age at onset/diagnosis in incidence studies with that in general PD research studies. METHODS: We systematically reviewed studies of PD incidence. We meta-analysed mean age at onset/diagnosis and age-stratum-specific incidence rates. We compared age-specific incidence rates in screening studies in the elderly with whole-population studies. We collated mean ages at onset/diagnosis in clinical studies of PD in five journals July-December 2016. RESULTS: In 17 studies reporting sufficient data to pool, mean age at onset/diagnosis was 69.6 years (95% CI 68.2-71.1), but heterogeneity was high (I2 = 96%). In ten of these studies reporting age at diagnosis specifically, the pooled mean age at diagnosis was slightly higher (71.6 [95% CI 70.6-72.6]) with lower, but still high, heterogeneity (I2 = 84%). In twelve whole-population studies reporting age-specific incidence rates, these peaked in age 70-79 (pooled incidence rate per 100,000 = 93.8 [95% CI 80.3-107.4]). Heterogeneity increased with each increase in age stratum (0% in youngest to 88% in oldest age stratum). Pooled age-specific incidence rates in five population-based screening studies of older age groups were several-fold higher than in whole-population studies. The mean of the reported mean ages at onset/diagnosis in recently published research studies was 60.8 (SD 5.6). CONCLUSION: The mean age of onset/diagnosis PD is about 70, although this may be an underestimate due to under-diagnosis in the elderly. Many published studies use age-unrepresentative subjects: the effect of this selection bias deserves further study.
OBJECTIVE: To describe, and explore heterogeneity in, age at onset/diagnosis in Parkinson's disease (PD) and compare mean age at onset/diagnosis in incidence studies with that in general PD research studies. METHODS: We systematically reviewed studies of PD incidence. We meta-analysed mean age at onset/diagnosis and age-stratum-specific incidence rates. We compared age-specific incidence rates in screening studies in the elderly with whole-population studies. We collated mean ages at onset/diagnosis in clinical studies of PD in five journals July-December 2016. RESULTS: In 17 studies reporting sufficient data to pool, mean age at onset/diagnosis was 69.6 years (95% CI 68.2-71.1), but heterogeneity was high (I2 = 96%). In ten of these studies reporting age at diagnosis specifically, the pooled mean age at diagnosis was slightly higher (71.6 [95% CI 70.6-72.6]) with lower, but still high, heterogeneity (I2 = 84%). In twelve whole-population studies reporting age-specific incidence rates, these peaked in age 70-79 (pooled incidence rate per 100,000 = 93.8 [95% CI 80.3-107.4]). Heterogeneity increased with each increase in age stratum (0% in youngest to 88% in oldest age stratum). Pooled age-specific incidence rates in five population-based screening studies of older age groups were several-fold higher than in whole-population studies. The mean of the reported mean ages at onset/diagnosis in recently published research studies was 60.8 (SD 5.6). CONCLUSION: The mean age of onset/diagnosis PD is about 70, although this may be an underestimate due to under-diagnosis in the elderly. Many published studies use age-unrepresentative subjects: the effect of this selection bias deserves further study.
Authors: Aleksandra A Szwedo; Camilla Christina Pedersen; Anastasia Ushakova; Lars Forsgren; Ole-Bjørn Tysnes; Carl E Counsell; Guido Alves; Johannes Lange; Angus D Macleod; Jodi Maple-Grødem Journal: Front Neurol Date: 2021-02-10 Impact factor: 4.003
Authors: Neil P Oxtoby; Louise-Ann Leyland; Leon M Aksman; George E C Thomas; Emma L Bunting; Peter A Wijeratne; Alexandra L Young; Angelika Zarkali; Manuela M X Tan; Fion D Bremner; Pearse A Keane; Huw R Morris; Anette E Schrag; Daniel C Alexander; Rimona S Weil Journal: Brain Date: 2021-04-12 Impact factor: 15.255
Authors: Svetlana Bivol; George D Mellick; Jacob Gratten; Richard Parker; Aoibhe Mulcahy; Philip E Mosley; Peter C Poortvliet; Adrian I Campos; Brittany L Mitchell; Luis M Garcia-Marin; Simone Cross; Mary Ferguson; Penelope A Lind; Danuta Z Loesch; Peter M Visscher; Sarah E Medland; Clemens R Scherzer; Nicholas G Martin; Miguel E Rentería Journal: BMJ Open Date: 2022-02-25 Impact factor: 3.006
Authors: Lieneke van den Heuvel; Luc J W Evers; Marjan J Meinders; Bart Post; Anne M Stiggelbout; Tom M Heskes; Bastiaan R Bloem; Jesse H Krijthe Journal: Mov Disord Date: 2020-10-27 Impact factor: 10.338