Table 1.
Characteristics of the studies included in meta-analysis
| Study | Type of study | P/C country | Mean age P/C | Type of alopecia | Diagnosis | DD Data collected |
|---|---|---|---|---|---|---|
| Aydingoz et al. [45] | Case-control | 43/46, Turkey | 25.9/age matched | TE, AnA/FPHL | Not described | Prevalence of iron deficiency, irondeficiency anemia in cases |
|
| ||||||
| Bregy and Trueb [26] | Cohort | 181, Switzerland | 42.39 | TE, AnA/FPHL | History, pull test, trichogram | Prevalence of iron deficiency |
|
| ||||||
| Chisti et al. [46] | Case-control | 100/100, India | 26.6/26.8 | TE, AnA/FPHL, AA | History, physical examination | Mean ferritin level among cases and controls |
|
| ||||||
| Deloche et al. [18] | Cohort | 2,910/2,200, France | Range 35–60 | Presumably TE, AnA/FPHL | History | Prevalence of iron deficiency, irondeficiency anemia |
|
| ||||||
| Deo et al. [47] | Cohort | 134, India | 30.96 | TE, AA, AnA/FPHL | History, physical examination, pull test | Prevalence of iron deficiency |
|
| ||||||
| Elethawi and Jabbar [31] | Case-control | 38/25, Iraq | 31.15/29.1 | TE | History, physical examination, pull test | Mean ferritin level among cases and controls |
|
| ||||||
| Ertug and Yilmaz [23] | Case-control | 455/196, Turkey | 29/31.3 | TE | History, physical examination + pull test | Mean ferritin level among cases and controls |
|
| ||||||
| Fatani et al. [48] | Cohort | 279, Saudi Arabia | 29.8 | TE | History + physical examination, pull test | Prevalence of iron deficiency |
|
| ||||||
| Gangaiah et al. [28] | Case-control | 40/40, India | 27/32.2 | TE, AnA/FPHL | History, physical examination | Prevalence of iron deficiency, iron-deficiency anemia |
|
| ||||||
| Gurel et al. [15] | Case-control | 80/80, Turkey | 26.41/25.79 | TE | History, physical examination | Mean ferritin level among cases and controls |
|
| ||||||
| Hamad et al. [19] | Case-control | 34/26, Egypt | 23/19.1 | TE | History, physical examination, pull test, trichogram | Mean ferritin level among cases and controls |
|
| ||||||
| Hodeib et al. [20] | Case-control | 40/20, Egypt | 28.1/27.4 | TE | History, physical examination, pull test, trichogram | Mean ferritin level among cases and controls |
|
| ||||||
| Ibrahem et al. [30] | Case-control | 80/20, Egypt | 25/23.2 | TE | History, physical examination, pull test | Mean ferritin level among cases and controls |
|
| ||||||
| Islamoglu and Sari [16] | Case-control | 103/125, Turkey | 25.7/26.2 | TE | Not described | Prevalence of iron deficiency in cases |
|
| ||||||
| Kantor et al. [32] | Case-control | 106/11, USA | 44.4/41.9 (28/36 in premenopausal subgroup) | TE, AnA/FPHL, AA | History, physical examination | Mean ferritin level among cases and controls |
|
| ||||||
| Karadag et al. [49] | Case-control | 63/50, Turkey | 29/28.4 | TE | History, physical examination, dermoscopy | Mean ferritin level among cases and controls |
|
| ||||||
| Karim et al. [21] | Case-control | 30/30, Bangladesh | 25.4/24.8 | TE | History, physical examination, pull test | Mean ferritin level and iron deficiency among cases and controls |
|
| ||||||
| Malkud [50] | Cohort | 180, India | 27.27 | TE + AnA/FPHL | History, physical examination, trichogram | Prevalence of iron deficiency |
|
| ||||||
| Moeinvaziri et al. [22] | Case-control | 30/30, Iran | 28.1/29.4 | TE | History, physical examination, trichogram | Mean ferritin level among cases and controls, prevalence of iron deficiency |
|
| ||||||
| Moltz [14] | Cohort | 125, Germany | 35.4 | AnA/FPHL | History, physical examination | Prevalence of iron deficiency |
|
| ||||||
| Nazik and Bengu [51] | Case-control | 39/30, Turkey | 26.3/24.7 | TE | History, physical examination, pull test, dermoscopy | Mean ferritin level among cases and controls |
|
| ||||||
| O'baidat et al. [52] | Case-control | 72/30, Jordan | 26/32 | TE | History, physical examination, pull test | Mean ferritin level among cases and controls, prevalence of iron deficiency |
|
| ||||||
| Olsen et al. [29] | Case-control | 381/76, USA | 44.5/39.9 (37/30 in premenopausal subgroup) | TE, AnA/FPHL | History, physical examination | Mean ferritin level among cases and controls, prevalence of iron deficiency, iron-deficiency anemia |
|
| ||||||
| Ozden et al. [53] | Cohort | 100, Turkey | 32 | TE + AnA/FPHL | History, physical examination | Prevalence of iron deficiency |
|
| ||||||
| Park et al. [54] | Case-control | 113/113, Korea | 42.9/40.1 | AnA/FPHL | History, physical examination | Mean ferritin level among cases and controls, prevalence of iron deficiency |
|
| ||||||
| Poonia et al. [55] | Cohort | 100, India | 30.1 | TE, AnA/FPHL | History, physical examination, pull test, trichogram | Prevalence of iron deficiency |
|
| ||||||
| Pradhan et al. [33] | Case-control | 60/60, Nepal | 33.9/35 | TE, AnA/FPHL, AA | History + physical examination | Mean ferritin level among cases and controls |
|
| ||||||
| Raichur et al. [25] | Cohort | 40, India | 25.18 | TE, AnA/FPHL | History, physical examination, pull test | Prevalence of iron deficiency |
|
| ||||||
| Rasheed et al. [42] | Case-control | 80/40, Egypt | 29.8/30.8 | TE, AnA/FPHL | History, physical examination, pull test, trichogram, dermoscopy | Mean ferritin level among cases and controls |
|
| ||||||
| Rushton et al. (1) [43] | Cohort | 50, UK | 32 (subgroup) | TE, AnA/FPHL | History, physical examination, trichogram | Prevalence of iron deficiency |
|
| ||||||
| Rushton (2) [56] | Cohort | 200, UK | No data | TE | History, physical examination, trichogram | Prevalence of iron deficiency |
|
| ||||||
| Sarkar et al. [57] | Case-control | 40/40, India | 24.3/23.1 | TE | History, physical examination, pull test, trichogram | Mean ferritin level among cases and controls |
|
| ||||||
| Sinclair [24] | Cohort | 194, Australia | Range 11–72 | TE, AnA/FPHL | History, physical examination, scalp biopsy, trichogram | Prevalence of iron deficiency and iron-deficiency anemia |
|
| ||||||
| White et al. [17] | Cohort | 20, UK | 38.25 | AA | Not described | Prevalence of iron deficiency |
|
| ||||||
| Zabolinejad et al. [58] | Cohort | 41, Iran | 28.1 | TE, AnA/FPHL, AA | History, physical examination, pull test | Prevalence of iron deficiency |
|
| ||||||
| Zhang et al. [27] | Cohort | 60, China | 34.4 | AnA/FPHL | History, physical examination, trichogram | Prevalence of iron deficiency |
P/C, patients/control; AnA, androgenetic alopecia; AA, alopecia areata.