Background
Methods
Study design
Study population
Study 1 | Study 2 | Validation study 3 | |
---|---|---|---|
Number of patients used | 190 | 250 | 162 |
Number of days | 9452 | 12431 | 3242 |
Mean age (± standard deviation) [years] | 36.9 (± 7.1) | 39.2 (± 6.9) | 38.8 (± 5.3) |
Median cycle length (range) [days] | 28 (9 – 38) | 28 (14 – 38) | 28 (7 – 33) |
Mean duration [days] of bleeding episodes (range) | 7.6 (4 – 60) | 6.9 (3 – 17) | 6.3 (3 – 14) |
Statistical analysis
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Hematological values (hemoglobin, hematocrit and serum ferritin)
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Additional diary information apart from BI, i.e., frequency of the BI SPOTTING, LIGHT, NORMAL and HEAVY during several defined time windows
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Age of the patient.
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occurrence of each single BI in the current bleeding episode,
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occurrence of each single BI in the entire diary, and
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number of days reporting each single BI during several time windows
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the actual bleeding episode comprising the day of interest
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the preceding episode
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all bleeding episodes during a time period most probably containing the last menstrual/withdrawal bleeding episode, here assessed as „all episodes extending at least 1?day into the 30?days preceding the actual episode“
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a baseline episode which reflects the inclusion criterion of the studies, defined here as the second heaviest episode during baseline. Heaviest was defined according to Fraser et al. [21] by using the means for MBLV per BI given there as a rough estimation.
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(M2) accounts for 1) number of days with heavy bleeding, 2) occurrence of normal bleeding, 3) occurrence of light bleeding and 4) occurrence of spotting. All parameters were assessed with respect to the actual bleeding episode. Furthermore, we included 5) hemoglobin (Hb), 6) serum-ferritin (Fe, including interaction with BI) and 7) age.
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(M3) accounts for the laboratory parameters only as given in (M1),
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(M4) accounts for the diary parameters only as given in (M1),
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(M5) accounts for age only.
Results
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hemoglobin and
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serum-ferritin including BI interaction.
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number of days with HEAVY bleeding in the current bleeding episode
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number of days with HEAVY bleeding in the preceding bleeding episode
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occurrence of HEAVY bleeding in the entire diary
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mean number of days with NORMAL bleeding during all episodes reaching into the last 30?days before current episode
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number of days with NORMAL bleeding in the second heaviest baseline-episode
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number of days with LIGHT bleeding in the second heaviest baseline-episode
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occurrence of LIGHT bleeding in the current episode
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occurrence of SPOTTING in the current episode
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Examination of the
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age of the patient
Model | Bayes’ Information Criterion (BIC) | Likelihood ratio test (with respect to initial model) | ||
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Likelihood ratio | Degrees of freedom | p value | ||
Initial model based solely on BI | 57861.7 | - | - | - |
(M1) | 55740.0 | 2514.4 | 42 | <0.001 |
(M2) | 55781.7 | 2379.8 | 30 | <0.001 |
(M3) | 55837.6 | 2114.0 | 9 | <0.001 |
(M4) | 55881.3 | 2290.2 | 31 | <0.001 |
(M5) | 55925.1 | 2016.5 | 8 | <0.001 |
Validation
Model | Day-wise correlation (s.e.) | Episode-wise correlation (s.e.) |
---|---|---|
(M1) | 0.73 (0.012) | 0.62 (0.031) |
(M2) | 0.73 (0.012) | 0.64 (0.030) |
(M3) | 0.72 (0.012) | 0.60 (0.032) |
(M4) | 0.70 (0.013) | 0.54 (0.033) |
(M5) | 0.69 (0.012) | 0.58 (0.032) |
Mean change (± standard deviation) | Association with investigators assessment, Spearman correlation (s.e.) n = 111 | Association with patients assessment, Spearman correlation (s.e.) n = 111 | |
---|---|---|---|
Estimated MBLV, by day | −9.02 ± 16.32 | 0.48 (0.084) | 0.44 (0.086) |
Measured MBLV, by day | −11.79 ± 20.51 | 0.42 (0.087) | 0.43 (0.086) |
Classification according estimated MBLV | Classification according measured MBLV | Total | |
---|---|---|---|
Excessive | Not excessive | ||
excessive | 380 (58.6%) | 64 (9.9%) | 444 (68.5%) |
87.4% of excessive | 30.0% of not excessive | ||
not excessive | 55 (8.5%) | 149 (23.0%) | 204 (31.5%) |
12.6% of excessive | 69.9% of not excessive | ||
Total | 435 (67.1%) | 213 (32.9%) | 648 (100%) |