Assessing physical symptoms during the postpartum period: reliability and validity of the primary health questionnaire somatic symptom subscale (PHQ-15)

Abstract

Introduction: This study aimed at establishing the reliability and validity of the primary health questionnaire (PHQ-15) somatic symptom severity subscale for postpartum women.

Methods: Women (N = 495) completed the PHQ-15 approximately 6 weeks postpartum during the baseline phase of a randomized controlled trial evaluating a writing intervention for postnatal health in England. Reliability was assessed using internal consistency statistics and convergent validity by comparing differences in self-reported physical health, health-related quality of life (QoL) and primary care usage by PHQ-15 symptom severity category.

Results: Cronbach’s α for the PHQ-15 was 0.73 and item-total statistics met recommended guidelines. Validity analyzes showed 6% of women reported severe symptoms, 17% medium, 50% low and 27% minimal symptoms. Women with severe symptoms reported poorer overall physical health, poorer physical health-related QoL and greater use of primary care. Women with severe symptoms also rated their baby’s health as worse and used primary care more for their baby.

Discussion: This study suggests the PHQ-15 has the potential to be a useful and valid measure of physical symptoms in postpartum women in high-income countries.

Keywords:

• Postpartum
• pregnancy
• physical health
• PHQ-15
• symptoms

Acknowledgements

We thank the following members of the HABiT team: Andy Field, Suzanne Lee, Andrew Eagle, Robert Bradley, Donna Moore, Gill Gyte, and Helen Smith. We gratefully acknowledge the contribution of all the women who took part in this study and NHS sites who recruited women to the study, in particular the principal investigators at sites: Lizzie Hamilton, Cecilia Iyasere, Anne-Marie Jones, Christina Koulouglioti, Helen Millward, Angela Philipson, Sandhya Rao, Heidi Ribchester, Jane Forbes, Susan Wellstead, and Louise Wills.

Disclosure statement

The views expressed are those of the authors and not necessarily those of the NHS, NIHR, or Department of Health. The authors report no other conflicts of interest. Clinical trial registration number: ISRCTN58399513.

Current knowledge on the subject

• Physical symptoms are common during pregnancy and after birth.

• Measures of physical symptoms are needed that are reliable and valid for use with perinatal women.

• The PHQ-15 is a measure of physical symptoms that has been widely used in other populations.

What this study adds

• This study provides evidence for the reliability and convergent validity of the PHQ-15 for postpartum women in high-income countries.

• Women with a high level of symptoms (6%) reported poorer physical health and greater use of primary care for themselves and their babies.

• Women with a high level of symptoms also reported poorer physical health-related QoL.

Additional information

Funding

This research was funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit funding scheme (Grant Reference Number PB-PG-0211-24096).