BC 1990 - breast cancer - data structure and protocols

Contents List

• BC 1990 - breast cancer
• BC 1990 data preparation: brief written protocol
• Specification of BC 1990 'pink form' format
• BC 1990 data form rubric

BC 1990 data preparation: brief written protocol

All patient records are converted into 'pink form' (1990) format (described below) if not already supplied in it. Results received as tables are converted into sets of synthetic records. The following routine checks (where appropriate) are performed on every compilation:

• Duplicate patient entries
• Patient identifier missing
• Randomisation date missing
• Treatment allocation missing
• Randomisation age missing
• Menopausal status missing
• Surgery type missing
• Axillary status missing
• Oestrogen receptor status missing
• Progesterone receptor status missing
• Contralateral breast cancer date missing
• Recurrence date missing
• Distant recurrence date missing
• Survival status missing
• Death date missing
• Randomisation date wrong, before 1945 or out of range
• Contralateral breast cancer date wrong or out of range
• Recurrence date wrong or out of range
• Distant recurrence date wrong or out of range
• Last follow-up or death date wrong or out of range
• Treatment allocation code unknown
• Randomisation age not in range 20-89
• Menopausal status code unknown
• Surgery code unknown
• Axillary status code unknown
• Oestrogen receptor status code unknown
• Progesterone receptor status code unknown
• Survival status code unknown
• Contralateral breast cancer flag error
• Recurrence flag error
• Distant recurrence flag error
• Cause of death given when alive

If an event such as the recurrence of disease is reported at a date later than the quoted last follow-up date, the last follow-up date is automatically changed to the later date. The completeness of follow-up is then calculated for the end of each calendar year. The distributions of randomisation dates, randomisation ages and time elapsed since last follow-up are checked for any significant imbalance between treatment groups in two ways as follows. Firstly, a t-test is applied to the difference between the mean value of each distribution for patients in each group with the corresponding mean for patients in the remainder. Secondly, an F-ratio is calculated for each distribution by comparing the variance between the groups with the variance within the groups. The distribution of time elapsed since last follow-up is also checked in these two ways for any significant imbalance between those patients with and those patients without a recorded recurrence of disease. Finally, the distribution of time elapsed since last follow-up is checked in the same two ways for any significant imbalance between patients in two categories of menopausal status (pre- or perimenopausal; postmenopausal), two categories of axillary nodal status (negative; positive), two categories of oestrogen receptor status (poor; positive) and two categories of progesterone receptor status (poor; positive).

Where patient serial numbers form an obvious sequence it is checked for missing numbers.

A tabulated breakdown of variables is produced for each trial, together (where relevant) with lists of patents in 'problematical' categories such as those with lapsed follow-up. In some cases Kaplan-Meier life-table curves are produced. Before trial data are finally incorporated into the overview, the analyses described above are sent to the participating trialist(s) for checking and approval.

Contact

Mike Clarke, Vaughan Evans, Liz Greaves, Jon Godwin or Richard Gray
EBCTCG Secretariat
C.T.S.U.
Radcliffe Infirmary
Oxford OX2 6HE
England
Tel. U.K.(44)-Oxford(1865)-57241; FAX: U.K.(44)-Oxford(1865)-58817

Specification of BC 1990 'pink form' format

BC 1990 data form rubric

[There will be a link to a picture of the 1990 BC data form here - in preparation]

GUARANTEE OF CONFIDENTIALITY OF DATA

ANY INFORMATION PROVIDED OVERLEAF TO THE EBCTCG SECRETARIAT WILL BE HELD SECURELY AND IN STRICT CONFIDENCE.

NOTES ON FORMAT OF DATA REQUESTED OVERLEAF

Special coding conventions

Please accompany these forms by an explanatory letter about any special coding conventions (e.g. on menopausal status, ER or PR) you have used, plus notes on any special features of the study(s) to which you wish to draw particular attention.

Dates that are not (or not yet) known exactly

either leave DAY blank, and give (approximate or provisional) month and year;
or leave DAY and MONTH blank, and just give approximate year.

BASELINE DATA

Patient identifier

Any convenient convention you wish, in case any correspondence becomes necessary. (If reporting several trials, please try to use a system that implicitly specifies both the trial and the patient.)

Date randomised

Please describe ALL patients EVER randomised, including even lost or withdrawn patients, and ignore all non-randomised patients.

Trt. gp. allocated

Treatment group number: 1 or 2 only, for 2-group trials, or a wider range for trials with more arms, as defined by you at the top of the form. N.B: even if, in reality, some quite different (or even opposite!) treatment was inadvertently given, what is wanted is the originally-allocated treatment. (For patients erroneously entered more than once, give only the first allocation.)

Entry age

Age at randomisation.

Menop. status on entry

0 or blank = not (yet) conveniently available; 1 = pre-, 2 = peri-, 3 = post-menopausal (includes bilateral ovarian ablation before randomisation). Use your own definitions of menopausal status at entry.

Surgery

Type of mastectomy first attempted: 0 or blank = not (yet) conveniently available; 1 = radical; 2 = total; 3 = simple; 4 = partial; 5 = none.

Axilla status on entry

0 or blank = not (yet) conveniently available; 1, 2, 3 = axillary clearance (1 = N0, 2 = N1-3, 3 = N4+); 4, 5 = axillary sample only (4 = N-, 5 = N+); 6, 7 = no sample (6 = clinically N-, 7 = clinically N+).

Est. Rec. on entry

Oestrogen receptor status: 0 or blank = not (yet) conveniently available; if exact value is not available use 1 = negative; 2 = marginal; 3 = postiive; otherwise use 4, 5, 6, 7, 8, 9 for < 10, 10-19, 20-29, 30-49, 50-99 and 100+ fmol/mg protein respectively.

Prg. Rec. on entry

Progesterone receptor status: 0 or blank = not (yet) conveniently available; if exact value is not available use 1 = negative; 2 = marginal; 3 = postiive; otherwise use 4, 5, 6, 7, 8, 9 for < 10, 10-19, 20-29, 30-49, 50-99 and 100+ fmol/mg protein respectively.

FOLLOW-UP DATA

2nd prim?

Second primary breast cancer? 1 = none recorded; 2 = contralateral; 3 = ipsilateral; 4 = contralateral and ipsilateral.

Approx. date of 2nd primary

Give the best estimate you can: see note above on approximate dates.

Recur?

Any recurrence? (N.B: excludes 2nd primary breast cancer) 1 = none recorded; 2 = some recurrence (distant or local).

Approx. date of 1st recur

Give the best estimate you can: see note above on approximate dates.

Dist. recur?

Any distant recurrence? 1 = none recorded; 2 = yes: ignore local disease and regional nodes.

Approx. date of 1st dist. recur

Give the best estimate you can: see note above on approximate dates.

Dead/other

1 = alive when last traced; 2 = known to be dead; 3 = lost despite extensive inquiries, but alive when last traced.

Date died/last traced

Date of death, or date last known to be alive, as accurately as possible: see note above on approximate dates.

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[End of document, updated to 3 June 2000]