Figure 1
Forest plot of meta-analysis of the prevalence estimates from all 42 studies.
Table 1
Estimated prevalence of ET by Continent for a cohort with an average age of 57.12 years old.
| CONTINENT | NUMBER OF STUDIES | ESTIMATED PREVALENCE | 99.2% CI |
|---|---|---|---|
| Africa | 1 | 5.42% | (0.73, 31.02) |
| Asia | 12 | 1.36% | (0.79, 2.33) |
| Australia | 1 | 1.82% | (0.24, 12.67) |
| Europe | 5 | 1.88% | (0.82, 4.26) |
| North America | 2 | 0.56% | (0.14, 2.13) |
| South America | 1 | 3.33% | (0.51, 18.99) |
[i] CI = confidence interval.
Figure 2
Prevalence of ET by continent.
Figure 3
Prevalence by age group and gender. Data from 15 studies.
Figure 4
Prevalence by study and age group in males (a), females (b), and both genders (c).
Table 2
Crude prevalence of ET in 42 population-based studies.
| AUTHOR | YEAR | COUNTRY | PREVALENCE (%) | AGES | EXAMINED ALL SUBJECTS (WHOM) |
|---|---|---|---|---|---|
| Li [24] | 1985 | China | 0.01 | All | No |
| Dotchin [25] | 2008 | Tanzania | 0.04 | All | No |
| Haimanot [26] | 1990 | Ethiopia | 0.04 | All | No |
| Osuntokun [23] | 1987 | Nigeria | 0.05 | All | Unclear from study description |
| Al Rajeh [27] | 1993 | Saudi Arabia | 0.2 | All | No |
| Attia Romdhane [28] | 1993 | Tunisia | 0.2 | All | No |
| Chouza [30] | 1994 | Uruguay | 0.2 | All | No |
| Tan [29] | 2005 | Singapore | 0.3 | ≥50 | No |
| Das [20] | 2009 | India | 0.35 | All | No |
| Hornabrook [31] | 1976 | New Guinea | 0.4 | All | Yes (field officer) |
| Salemi [32] | 1994 | Italy | 0.4 | All | Yes (neurologists) |
| Haerer [33] | 1982 | USA | 0.4 | ≥40 | No |
| Inzelberg [21] | 2006 | Israel | 0.5 | ≥65 | Yes (neurologists) |
| Acosta [34] | 1989 | Spain | 0.6 | All | Yes (nurses, General practitioners) |
| Aharon-Peretz [48] | 2012 | Israel | 0.7 | ≥51 | No |
| Glik [35] | 2009 | Israel | 0.8 | ≥65 | Yes (neurologist) |
| Mancini [36] | 2007 | Italy | 0.8 | ≥41 | Yes (General practitioners) |
| Okubadejo [47] | 2012 | Nigeria | 1.2 [1.2] | All | No but information provided on sensitivity of screening instrument |
| Larsson [12] | 1960 | Sweden | 1.4 | All | No |
| Louis [45] | 2011 | Bangladesh | 1.6 | >18 | Yes (using spirals) |
| Ozel [49] | 2006 | Turkey | 1.6 | 18-60 | No |
| Bharucha [37] | 1988 | India | 1.7 | All | No |
| Eliazen [55] | 2019 | Faroe Islands | 2.9 | ≥40 | No |
| Sur [38] | 2008 | Turkey | 3.1 | ≥18 | Yes |
| Wenning [44] | 2005 | Austria | 3.4 | 50–89 | Yes (neurologists, geriatricians, other medical specialists) |
| Dogu [10] | 2003 | Turkey | 3.5 | ≥40 | Yes (neurologists) |
| Oh [52] | 2014 | Korea | 3.6 | ≥65 | Yes |
| Yao [53] | 2015 | China | 3.6 | ≥45 | No |
| Louis [13] | 1995 | USA | 2.2 [3.9] | ≥65 | No but information provided on sensitivity of screening instrument |
| Louis [54] | 2016 | USA | 4.5 | ≥18 | Yes |
| Sun [57] | 2020 | China | 4.8 | ≥55 | No |
| Louis [41] | 2009 | USA | 5.5 | ≥65 | Yes (handwriting samples reviewed by movement disorder specialist) |
| Guler [56] | 2019 | Turkey | 5.75 | ≥18 | No |
| Bergareche [39] | 2001 | Spain | 2.4 [6.4] | ≥65 | No but information provided on sensitivity of screening instrument |
| Liu [46] | 2011 | China | 6.5 | ≥55 | No |
| Liu [22] | 1997 | China | 6.5 | ≥50 | Yes (neurologists) |
| Benito-Leon [40] | 2003 | Spain | 4.9 [7.0] | ≥65 | No but information provided on sensitivity of screening instrument |
| Barbosa [50] | 2013 | Brazil | 7.4 | ≥64 | No |
| Seijo-Martinez [51] | 2013 | Spain | 8.6 | ≥65 | Yes |
| Rautakorpi [11] | 1982 | Finland | 6.2 [9.7] | ≥40 | No but information provided on sensitivity of screening instrument |
| Moghal [42] | 1994 | Canada | 14.3 | ≥65 | Yes |
| Khatter [43] | 1996 | USA | 20.5 | ≥65 | Yes (not specified) |
[i] Studies are ordered from lowest to highest prevalence (%).
All values in brackets account for the sensitivity of the initial screening process (i.e., values are higher because they include an estimate of the number of false negatives).
In bold are the studies that: (1) either examined all subjects or provided information on screening questionnaire and (2) provided separate age-stratified estimates of prevalence among elderly aged 60 and older.
Table 3
Crude prevalence of ET (older age categories) in population-based prevalence studies.
| AUTHOR | YEAR | COUNTRY | PREVALENCE ≥60 YEARS* (%) | PREVALENCE IN OLDEST AGE GROUP (%) |
|---|---|---|---|---|
| Inzelberg [21] | 2006 | Israel | 0.5 (≥65 years) | 1.2 (≥80 years) |
| Glik [35] | 2009 | Israel | 0.8 (≥65 years) | 1.5 (≥80 years) |
| Mancini [36] | 2007 | Italy | 2.1 (≥61 years) | 3.3 (81–90 years) and 3.6 (≥90 years) |
| Salemi [32] | 1994 | Italy | 2.3 (≥60 years) | 5.4 (≥80 years) |
| Oh [52] | 2014 | Korea | 3.6 (≥65 years) | 1.4 (≥80 years) |
| Louis [13] | 1995 | USA | 2.2 [3.9] (≥65 years) | 4.6 [8.4] (≥85 years) |
| Hornabrook [31] | 1976 | New Guinea | 4.1 (≥60 years) | No data |
| Louis [54] | 2016 | USA | 5.1 (≥ 65 years) | 10.9 (≥80 years) |
| Louis [41] | 2009 | USA | 5.5 (≥65 years) | 9.9 (85–94 years), 21.7 (≥95 years) |
| Dogu [10] | 2003 | Turkey | 6.3 (≥60 years) | 8.7 (≥80 years) |
| Bergareche [39] | 2001 | Spain | 2.4 [6.4] (≥65 years) | 9.7 [12.9] (≥85 years) |
| Benito-Leon [40] | 2003 | Spain | 4.8 [7.0] (≥65 years) | 7.3 [10.6] (≥85 years) |
| Seijo-Martinez [51] | 2013 | Spain | 8.6 (≥65 years) | 11.2 (≥85 years) |
| Sur [38] | 2008 | Turkey | 11.5 (≥61 years) | 9.3 (≥71 years) |
| Moghal [42] | 1994 | Canada | 14.3 (≥65 years) | No data |
| Rautakorpi [11] | 1982 | Finland | 9.0 [15.6] (≥60 years) | 11.8 [20.7] (≥80 years) |
| Khatter [43] | 1996 | USA | 20.5 (≥65 years) | No data |
| Okubadejo [47] | 2012 | Nigeria | 26.1 (≥65 years) | 42.9 (≥85 years) |
[i] Table includes studies: (1) either examined all subjects or provided information on screening questionnaire and (2) provided separate age-stratified estimates of prevalence among elderly aged 60 and older.
Studies are ordered from lowest to highest prevalence (%) in the ≥60 year age stratum.
All values in brackets account for the sensitivity of the initial screening process (i.e., values are higher because they include an estimate of the number of false negatives).
* In some studies, age stratum was ≥60 while in others (as indicated), it was ≥61 or ≥65.