HD 1991 - Hodgkin's disease - data structure and protocols

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HD 1991 data preparation: brief written protocol

Strict confidentiality of trial results is observed. Information is held in the Clinical Trial Service Unit computers in a form which can be accessed only by known individuals. All patient records are converted into 'pink form' (1991) format (described below) if not already supplied in it. Results received as tables are converted into sets of synthetic 'pink form' records. The following routine checks (where appropriate) are performed on every 'pink form' compilation: The total numbers of patients and the distributions of randomisation age, disease stage, systemic symptoms and primary treatment outcome are checked for any significant imbalance between treatment groups. These four distributions are compared as follows. Patients are grouped into three categories according to randomisation age (below 30 years; 30 - 49 years or unknown; 50 years or above) and a chi-squared test is applied to the population of the three categories found in each treatment group. Similarly, five categories are formed for disease stage (I; II; III; IV; unknown), three for systemic symptoms (absent; present; unknown) and three for primary treatment outcome (complete remission; other failures; unknown) and these are tested in the same way as the categories formed for randomisation ages.

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 randomisation is checked in the same two ways for any significant imbalance between patients in four categories of disease stage (I; II; III; IV), two categories of systemic symptoms (absent; present) and two categories of primary treatment outcome (complete remission; other failures).

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 patients in 'problematical' categories such as those with lapsed follow-up, uncertain death cause or second malignancy site. Graphs of accrual date and the proportion of living patients still on follow-up as a function of time from randomisation by treatment allocation are also produced, together with Kaplan-Meier life-table curves. 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

Please address inquiries concerning data preparation and checking to:

Specification of HD 1991 'pink form' format

Item Description FORTRAN Columns Details Abbreviation
0  Trial/stratum identifying code  I6  1 - 6  Trial 
1  Patient identifier (or sequence number)  A12  8 - 19  Patient 
2  Gender  I1  21 
Value Description Abbreviation
1  Male  M 
2  Female  F 
 		 Sex 
3  Date of birth  I6  23 - 28  DDMMYY  Birth Date
4  Laparotomy  I1  30 
Value Description Abbreviation
1  No  No 
2  Yes  Yes 
 		 Lap. 
5  Disease stage  I1  32 
Value Description Abbreviation
1  I  I 
2  II  II 
3  III  III 
4  IV  IV 
 		 Stage 
6  Systemic symptoms  I1  34 
Value Description Abbreviation
1  Absent  No 
2  Present  Yes 
 		 Symp. 
7  Date of initial treatment/diagnosis  I6  36 - 41  DDMMYY  1-Trt. Date 
8  Randomisation date  I6  43 - 48  DDMMYY  Entry Date 
9  Treatment group allocated (as on master list)  I1  50  Trt. Grp 
10  Primary treatment outcome  I1  52 
Value Description Abbreviation
1  Complete remission  CR 
2  Other failures  Ofail 
 		 Prim. Outc 
11  Outcome evaluation date  I6  54 - 59  DDMMYY  Outcome Date 
12  Recurrence  I1  61 
Value Description Abbreviation
1  No  No 
2  Yes  Yes 
 		 Rec 
13  Date of first recurrence  I6  63 - 68  DDMMYY  Rec. Date 
14  State when last traced  I1  70 
Value Description Abbreviation
1  Alive  Alive 
2  Dead  Dead 
3  Lost  Lost 
 		 State 
15  Date died or last traced  I6  72 - 77  DDMMYY  L.F.U. 
16  Cause of death (extra category); there is also a 'pre-diktat' Cause of Death item, with the same coding, in form columns 79-80  I2  82 - 83 
Value Description Abbreviation
1  Iatrogenic  Iatro 
2  Infective  Infec 
3  Leukaemia  Leuk 
4  Solid neoplasm  Neop2 
5  Cardiovascular  CardV 
6  - 
7  - 
8  Extraneous cause  Extra 
9  Not 1-5,8,13,14 and not Hodgkin's dis.  NotHD 
10  Not Hodgkin's disease  NotHD 
11  Hodgkin's disease  HD 
12  Unascertainable cause  Unkn. 
13  Pulmonary  Pulmo 
14  Non-Hodgkin's lymphoma  NonHL 
 		 Death 
17  Name (if given), cause of death and comments  A  85 - end  Name 
Missing or unknown items are left blank or set to zero.

HD 1991 data form rubric

GUARANTEE OF CONFIDENTIALITY OF DATA

NOTES ON FORMAT OF DATA REQUESTED OVERLEAF

Special coding conventions

BASELINE DATA

Patient identifier

FOLLOW-UP DATA

Primary treatment outcome


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[End of document, updated to 1 September 2000]