NCDS Age 44 Biomedical Sweep

Sweep details

Dates September 2002 to March 2004
Age 44-45
Achieved sample 9377 (cohort members)
Respondents Cohort members
Fieldwork agency NatCen Social Research
Survey mode Face to face (nurse visit) and paper self-completion questionnaires
Data access
The majority of variables are available under EUL [8731], with only the sensitive and disclosive ones under Special Licence [5594].

The NCDS biomedical sweep was designed to obtain objective measures of ill-health and biomedical risk factors.

The broad aims were to explore the impact of developmental, environmental and lifestyle factors on ill-health, and physiological and psychological function among adults in early middle age; to investigate the effect of such factors on geographical and socioeconomic health inequalities; and to make possible comparisons between these adults in early middle age and members of the MRC funded 1946 birth cohort at the same age.

The research was also intended to address a wide range of specific hypotheses relating to anthropometry, cardiovascular, respiratory and allergic diseases, visual and hearing impairment, and mental ill-health.

The survey was administered by nurses and involved the following:

  • Vision: measures of near vision in right and left eyes (using appropriate visual correction), with and without pinhole viewer; stereo vision; distance vision (using appropriate visual correction).
  • Blood pressure and pulse: three measures of systolic and diastolic blood pressure and resting pulse.
  • Prescription drugs: all prescribed drugs taken, by name and BNF code.
  • Hearing: thresholds of hearing in right and left ears at 1kHz and 4kHz.
  • Standing height, sitting height, weight, waist circumference, hip circumference.
  • Lung function: three measures (from up to five attempts) of forced vital capacity (FVC), forced expiratory volume (FEV1) and peak flow (PF).
  • Eye measurements using autorefractor: sphere, cylinder and axis of right and left eyes.
  • (CASI): AUDIT and supplementary questions about drinking alcohol; adverse childhood experiences.
  • CIS-R interview: modules covering appetite, fatigue, concentration and forgetfulness, sleep problems, irritability, depression, depressive ideas, anxiety, phobias, and panic
  • Two paper self-completion questionnaire asked participants about: sun exposure, physical activity, hearing, eyesight, pain, household circumstances, social support, general health, diet, employment and working conditions, life events and (women only) menopause, contraception and HRT.

Non-fasting blood samples were collected and (with consent) immortalised cell lines were created and DNA extracted and stored for medical research purposes. A wide variety of assays of the blood were conducted.

Special features of the age 44 biomedical survey

Collection of blood samples

Non-fasting blood samples were collected from all willing participants on which a full range of biochemical markers were measured: C reactive protein, Fibrinogen, HbA1c, HDL and total cholesterol, IGF Specific IgE, Total IgE, tissue Plasminogen Activator, Trigycerides, Von Willebrand Factor and Serum 25-Hydroxyvitamin D.

When combined with the rich life-history information collected in the NCDS, these data allow for detailed examination of the life course factors affecting these biomarkers and the impact they have on aspects of health.

The genetic data created from the DNA extracted from blood samples has led to important breakthroughs in our understanding of the genetic underpinnings of common medical conditions such as diabetes, rheumatoid arthritis and coronary heart disease. Genetic data have been used alongside those from other blood donors as part of the the Wellcome Trust Case Control Consortium. This allows scientists to compare a ‘control’ group of healthy people to those who have certain diseases. By doing this, scientists can start to unpick which factors – or in this case genes – might be related to different medical conditions.


Over the years, NCDS has collected a vast amount of information about the mental health of its participants, which allows for the study of mental health trajectories and the lifetime consequences of poor mental health.

The NCDS biomedical survey included a very detailed assessment of mental health, the CIS-R, which includes questions on appetite, fatigue, concentration and forgetfulness, sleep problems, irritability, depression, depressive ideas, anxiety, phobias, and panic, as way of identifying common mental disorder. The inclusion of the CIS-R allowed researchers to examine particular aspects of mental health in more detail than was previously possible.

Objective anthropometric measurements

For the first time since childhood the biomedical survey collected objective measures of height and weight.

Obesity is a major health concern and research using NCDS has played a major role in furthering our understanding of the causes and consequences of being overweight. However, until the biomedical survey, NCDS relied on participants self-reporting their height and weight which will clearly be less accurate than objective measurements.

In addition, nurses also measured sitting height, waist circumference and hip circumference and together these measurements provide an invaluable resource for further research into the lifestyle factors leading to obesity and overweight in mid-life and the ongoing consequences for future health.

Objective measurements of height and weight have also been recorded in the BCS70 Age 46 sweep, which will allow for cross-cohort comparisons.


The menopause is clearly an important phase in women’s lives that can have significant impacts upon other aspects of health and well-being. The NCDS began asking women about menopausal symptoms in the biomedical sweep.

Further questions have been asked in subsequent sweeps (at 50 and 55), providing researchers with opportunities to explore the lifetime factors associated with differential timing of the menopause and to answer important questions about how menopausal symptoms may be associated with other aspects of life.


  • User guides
  • Questionnaires
  • Technical reports
  • Data notes
  • Additional
User guides

NCDS Age 44 User Guide to the Biomedical Dataset

User Guide to the Age 44 Biomedical Sweep of NCDS

Date published: 16/12/2020

Handling missing data in the National Child Development Study – User Guide

This user guide aims to describe and illustrate a straightforward approach to missing data handling, while detailing some more general considerations around missing data along the way.

Date published: 12/07/2021
PDF: 657,33 KB


NCDS Birth-Age 55 Response and Deaths Dataset User Guide

This document accompanies the deposit of the NCDS Response and Deaths dataset at the UK Data Service in March 2015.

Date published: 01/03/2015
PDF: 647,55 KB


Partnership Histories Guide (1974-2013)

Date published: 01/11/2017
PDF: 374,82 KB


Activity Histories Guide (1974-2013)

Date published: 01/10/2016
PDF: 594,01 KB


NCDS Age 44 Biomedical Questionnaire Documentation

Paper representation of the Age 44 Biomedical questionnaire

Date published: 01/05/2010
PDF: 1,48 MB


NCDS Age 44 Self-Completion Booklet 1

Self-completion booklet for the NCDS Age 44 Biomedical sweep

Date published: 01/05/2003
PDF: 611,3 KB


NCDS Age 44 Self-Completion Booklet 2

Self-completion booklet 2 for age 44 biomedical sweep of NCDS

Date published: 01/05/2003
PDF: 211,94 KB

Technical reports

NCDS Age 44 Biomedical Technical Report

Technical Report for the age 44 biomedical sweep of NCDS

Date published: 01/07/2006
PDF: 2,78 MB

Data notes

No material of this type is available.


Deriving highest qualification in NCDS and BCS70

This Data Note explains the derivation of variables on Highest Educational Qualification obtained by cohort members in the National Child Development Study (NCDS) and the 1970 British Cohort Study (BCS70).

Date published: 01/01/2011
PDF: 514,11 KB


Standard Operating Procedure for Von Willebrand Factor (vWF) antigen ELISA

Date published: 03/05/2005
PDF: 87,44 KB


Standard Operating Procedure for Triglycerides

Date published: 01/02/2002
PDF: 141,67 KB


Standard Operating Procedure for Total IGE

Date published: 22/05/2003
PDF: 223,58 KB


Standard Operating Procedure for tissue Plasminogen Activator

Date published: 03/05/2005
PDF: 99,62 KB


Standard Operating Procedure for specific IGE

Date published: 12/12/2001
PDF: 211,27 KB


Standard Operating Procedure for IGF1

Date published: 01/02/2002
PDF: 132,58 KB


Standard Operating Procedure for High sensitivity CRP assay

Date published: 03/05/2005
PDF: 78,82 KB


Standard Operating Procedure for HDL cholesterol

Date published: 01/02/2002
PDF: 155,15 KB


Standard Operating Procedure for HbA1c using the TOSOH A1c2.2

Date published: 01/11/2001
PDF: 205,02 KB


Standard Operating Procedure for Determination of clottable fibrinogen

Date published: 03/05/2005
PDF: 80 KB


Standard Operating Procedure for Cholesterol

Date published: 01/02/2005
PDF: 117,92 KB


Coded Manikins

Date published: 01/01/2005
PDF: 57,7 KB


NCDS Ethical Review and Consent

Review of the ethical practices throughout NCDS

Date published: 02/06/2014
PDF: 1,76 MB

Contact us

Centre for Longitudinal Studies
UCL Social Research Institute

20 Bedford Way
London WC1H 0AL