Table 1.
Study design and results of included studies
| First author [Ref.], year | Study type |
Characteristics of enrolled subjects (completed study) | Objective measures | Objective assessment of hair growth | Subjective assessment of hair growth | |||
|---|---|---|---|---|---|---|---|---|
| randomized | controlled | blinded | half-head | |||||
| Anitua [29], 2017 | No | No | Yes | No | 19 (19) 12 M, aged 27–60, stage III–VI; 2 F, aged 32–60, stage II-frontal |
#1–4 Computerized phototrichogram 1. Hair density 2. Hair diameter 3. Terminal/vellus-like hair ratio 4. Thin/regular/thick hair shafts among terminal follicles 5. Independent observer clinical evaluation (mean improvement score using global macro-photographs) 6. Epidermal thickness perivascular inflammatory infiltrate, rete ride number, terminal/miniaturized hair ratio, and collagen, reticular fiber and elastic fiber mesh quantity (3 mm punch biopsies) 7. Proliferative epidermal/follicular cells, newly formed blood vessels, and presence of bulge stem cell niches (immunohistochemistry) |
1. Yes (p < 0.05) 2. Yes (p < 0.05) 3. Yes (p < 0.05) 4. Yes (p < 0.05) 5. Yes; 0.75/1a 6. Yes (p < 0.05 for most) 7. Yes (p < 0.05 for most) |
Patient self-satisfaction score following a Likert scale: 7 = very satisfied, 6 = satisfied, 5 = indifferent, 1 = unsatisfied, and 0 = very unsatisfied; most patients (15/19) declared noticeable hair loss decrease, 13/19 declared noticeable improvement in hair quality and appearance, and 11/19 stated they would continue with PRGF treatment |
| Alves [33], 2016 | Yes | Yes | Yes | Yes | 25 (24) 11 M, aged 18–65, stage II–V; 11 F, aged 18–86, stage I–III |
#1–6: Phototrichogram & global photography 1. Anagen hair (%) 2. Telogen hair (%) 3. Anagen:telogen ratio 4. Hair density 5. Terminal hair density 6. Hair count |
PRP vs. placebo: 1–3, 5, 6. No (p > 0.05) 4. Yes, at 3 and 6 mos (p < 0.05) PRP vs. baseline: 1–5. Yes (p < 0.05) 6. No (p > 0.05) |
n.a. |
| Gentile [34], 2015 | Yes | Yes | Yes | Yes | 23 (20) 20 M, aged 19–63, stage IIa–IV |
#1–3: Computerized phototrichogram and global photography: 1. Hair count & total hair density 2. Terminal hair density 3. Epidermal thickness & hair follicle density (3-mm punch biopsy) 4. Keratinocyte proliferation and small blood vessel proliferation around hair follicles (immunohistochemistry) 5. Relapse of AGA |
1. Yes (p < 0.0001) 2. Yes (p = 0.0003) 3. Yes (p < 0.05) 4. Yes (p < 0.05) 5. Four patients reported progressive hair loss at 12–16 mos |
Physician and patient global assessment scale) – results not reported |
| Cervelli [28], 2014 | Yes | Yes | Yes | Yes | 10 (10) 10 M, aged 20–52, stage IIa–IV |
#1–4: Computerized phototrichogram & global photography: 1. Hair count 2. Hair density 3. Terminal hair density 4. Epidermal thickness & hair follicle density (3-mm punch biopsy) 5. Percentage of Ki67+ keratinocytes & blood vessel density (immunohistochemistry) |
1. Yes (p < 0.0001) at 3 mos 2. Yes (p < 0.0001) at 3 mos 3. Yes (p = 0.0003) at 3 mos 4. Yes (p < 0.05) at 3 mos 5. Yes (p < 0.05) at 14 wks |
Physician and patient global assessment scale - results not reported |
| Singhal [12], 2015 | No | Yes | No | No | 20 (20) 16 M, aged 25–32; 4 F aged 32–35 |
1. Hair count (hair pull test) 2. Hair growth, hair volume, hair quality, fullness (global photographs) |
1. Yes, pulled hair count was reduced by 65% (vs 0% in controls)a 2. Yes, hair growth noted in 6 patients after 7 days but in 4 patients after 15 days; yet, all patients (10) had good hair growth after 3 mosa |
n.a. |
| Gupta [32], 2017 | - | No | No | No | 30 (30) 30 M, aged 25–35, stage III–VII |
1. Hair density (CapilliCare trichoscan) 2. Hair diameter (CapilliCare trichoscan) 3. Independent observer clinical evaluation (global macrophotographs) |
1. Yes (39.7±16.5% increase compared to baseline)a 2. Yes (39.8±17.2% increase compared to baseline)a 3. Average improvement = 30.2±12.2% |
Patient self-assessment questionnaire: treatment group reported 30±13.1% mean improvement (range 10–70%); 93.3% reported complete cessation of hair fall by 2 mos; 66.7% reported increase in hair growth; 36.7% reported improvement in hair texture |
| Schiavone [36], 2014 | - | No | No | No | 64 (64) 42 M, mean age 28, stage II–V; 22 W, mean age 32, stage I–II |
1. Hair count and hair thickness using Jaeschke 15 point scale rating of clinical change (macrophotographs examined by 2 independent evaluators) | 1. Yes (mean change in clinical rating of 3.2 and 3.9)a | n.a. |
| Gkini [40], 2014 | No | No | No | No | 22 (20) 18 M, aged 24–72, stage II-5a; 2 F, aged 58–72, stage I |
1. Hair pull test 2. Hair density & quality (dermoscopic photomicrographs and macroscopic photographs) |
1. Yesa 2. Yes, p < 0.001; overall improvement in hair density & quality per photographs |
Patient self-assessment questionnaire: mean result rating of 7.1 on a 1–10 scale; 85% reported improvement in hair quality and thickness; 65% reported increases in hair density |
| Khatu [35], 2014 | No | No | No | No | 11 (11) 11 M, aged 20–40, stage II–IV |
1. Hair pull test 2. Hair count (Trichoscan) 3. Hair loss (clinical examination, macroscopic photos) |
1. Yes (81.81% achieved a negative pull test at 12 wks)a 2. Yes (average mean gain of 22.09 follicular units/cm2)a 3. Yes (moderate improvement in hair volume and coverage with reduction in hair loss)a |
Patient satisfaction questionnaire: mean overall satisfaction rating of 7 out of 10 |
| Takikawa [37], 2011 | - | Yes | No | Yes | 26 (26) 16 M, 10 F, aged 28–59, thin hair in the frontal or parietal areas |
1. Mean number of hairs (digital and dermoscopic imaging) 2. Mean cross sections of hairs (digital and dermoscopic imaging) 3. Epidermal thickness, collagen and blood vessel density around hair follicles (4-mm punch biopsy) |
1. Yesa 2. Yes (p < 0.01) 3. Yesa |
Patients reported less depilation when shampooing, greater bounce/resilience of hair, maintenance of healthy hairs |
| Puig [30], 2016 | Yes | Yes | Yes | No | 26 (26) 26 F, stage II |
1. Hair count (photography) 2. Hair mass index (Cohen HairCheck® system) |
1. No (p = 0.503) 2. No (p = 0.220) |
13.3% of treatment group vs. 0% of control group reported substantial improvement in hair loss, rate of hair loss, hair thickness, and ease of managing/styling hair; 26.7% of treatment group vs. 18.3% of control group reported feeling coarser/heavier hair |
| Mapar [31], 2016 | Yes | Yes | Yes | Yes | 19 (17) 17 M, aged 24–45, stage IV–VI |
1. Terminal hair count (magnifying glass) 2. Vellus hair count (magnifying glass) |
1. No (p = 0.25 at 6 mos) 2. No (p = 0.23 at 6 mos) |
n.a. |
M, male; F, female; wks, weeks; mos, months.
a
p value not reported.