Data collection
Data were collected from the National Health (NHS) Service
Cerner® database and a private healthcare database
(Carebit, London UK). Patient demographic data collected, included age
and ethnicity. Clinical data was extracted from patient notes and
referral letters, including menstrual frequency; hyperandrogenism and
hypoestrogenism symptoms; exercise history; weight loss preceding
amenorrhoea; psychological stress; and occupation. Occupations were
stratified using International Standard Classification of Occupations
2008 (ISCO-08).15 Data was collected on patient
medical history, including fractures, eating disorders (ED),
psychological comorbidities and family history. Patients BMI was
collected and used to categorise patients as: underweight
(<18.5kg/m2); healthy
(18.5-24.9kg/m2); overweight
(25-29.9kg/m2); obese
(30-39.9kg/m2); or morbidly obese
(≥40kg/m2). Ultrasonography reports provided
endometrial thickness and polycystic ovarian morphology (PCOM) data.
Reports provided BMD and Z-score of L2-L4 segment and femora from dual
energy X-ray absorptiometry (DEXA) scans. Blood results either from the
first clinic visit or GP referral letter were examined for LH
[reference value >3 IU/L] and FSH [ reference value
>6 IU/L] (used to calculate LH:FSH ratio [reference
value <2]), estradiol [reference value
>100pmol/L], thyroid-stimulating hormone (TSH)
[reference range 0.4-4.0mU/L], free T4 (fT4) [reference range
9.0-25.0pmol/l], and prolactin [reference range 45-375IU/mL].
Given the retrospective nature of this study, it was expected that a
significant proportion of patients would have missing data; to overcome
this comparison between the FHA and PCOS groups were only performed when
the majority (≥50%) of patients had data available.