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The FIBROID Registry

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Table 3: Imputations and Coding for Modeling


Imputation of Missing Data

Coding of Variable for Modeling Purposes

All continuous variables (age, BMI, length of procedure, uterine volume, fibroid size)

Imputed as medians of the variable

Value of the variable itself


Number of fibroids

Imputed to 5

Value of the variable itself


Imputed as Caucasian/other

2 groups for race: Caucasians or others vs. African Americans (reference group)

History of pregnancy

Used data from variables—gravida, para, spontaneous abortion, ectopic—to define variable. If still missing imputed to "nulligravid"

Nulliparous or nulligravid vs. parous


Imputed as "non smoker"


Previous procedures

Imputed to "none"

Any vs. none (ref.)

Previous medical therapy

Imputed to "none"

Any vs. none (ref.)

Fibroid morphology

Lumped missing with subserosal & intra/trans mural

Submucosal vs. others (ref.)


Missing lumped with other symptoms

Heavy bleeding, pelvic pain, bulk vs. others (ref)

DVT prop.

Imputed to "no"

yes vs. no (ref)

Prophylactic antibiotics

Imputed to "no"

yes vs. no (ref)

Vessel embolized

Excluded patients missing or with no vessel embolized

UA bilateral vs. UA single (ref.)

Core site

No requirement

yes vs. no (ref)

Practice type

No requirement

academic vs. other (ref)

Site experience

Initial no. of cases imputed as 0


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