Neurocognitive effects of treatment for childhood cancer
Abstract
We review research on the neuropsychological effects that central nervous system (CNS) cancer treatments have on the cognitive abilities of children and adolescents. The authors focus on the two most common malignancies of childhood: leukemias and brain tumors. The literature review is structured so as to separate out earlier studies, generally those published prior to 1995, as opposed to manuscripts that have been published within the past decade. This is an important distinction for both leukemia and brain tumors. Earlier studies were ground breaking in that they began to map out what could be expected in terms of intelligence and academic problems in survivors of pediatric malignancies. Survivorship in this population has and continues to markedly increase and this is largely due to changes in treatment protocols. Research on neurocognitive effects of disease and treatment in pediatric oncology has become increasingly sophisticated, and this literature review not only reflects this trend, but highlights the growing collaboration between neuropsychology, cognitive neuroscience, and neuro-imaging. Thus, our goal was to provide a historical foundation, lead the reader towards the progression of research methodology up to the current state of the art, and perhaps most importantly, discuss future directions. These directions are especially relevant to the concepts of remediation and treatment of cognitive problems, and this is emphasized at the conclusion of the review.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Ionizing radiation can damage the CNS, causing changes to cognitive function, inducing fatigue, and generating performance decrements.
“Ionizing radiation can damage the CNS, causing changes to cognitive function, inducing fatigue, and generating performance decrements [2,30,42,43,44,45,46,47,48,49,50,51].”
From Space Radiation: The number one risk to astronaut health beyond low earth orbit (2014) · cites this paper as [42]
Cites
SEER Cancer Statistics Review, 1975-2003
Ries, L. A. G., Harkins, D., Krapcho, M. F., Mariotto, A. B., Miller, B., Feuer, E. J., Clegg, L. X., Eisner, M. P., Horner, M., Howlader, N., et al. (2006) · Digital Archive @ GSU · Cited by 11,404 · see citing works
Late neurocognitive sequelae in survivors of brain tumours in childhood
Mulhern, R. K., Merchant, T. E., Gajjar, A. J., Reddick, W. E., & Kun, L. E. (2004) · The Lancet Oncology · doi:10.1016/s1470-2045(04)01507-4 · Cited by 868 · see citing works
Swinson, J. M. (2013) · Educational Psychology in Practice · doi:10.1080/02667363.2013.853380 · Cited by 609 · see citing works
Ris, M. D., Packer, R. J., Goldwein, J. L., Jones-Wallace, D., & Boyett, J. M. (2001) · Journal of Clinical Oncology · doi:10.1200/jco.2001.19.15.3470 · Cited by 529 · see citing works
Meadows, A., Massari, D. J., Fergusson, J., Gordon, J., Littman, P., & Moss, K. (1981) · The Lancet · doi:10.1016/s0140-6736(81)91216-2 · Cited by 438 · see citing works
Palmer, S. L., Goloubeva, O. G., Reddick, W. E., Glass, J. O., Gajjar, A. J., Kun, L. E., Merchant, T. E., & Mulhern, R. K. (2001) · Journal of Clinical Oncology · doi:10.1200/jco.2001.19.8.2302 · Cited by 400 · see citing works
Mulhern, R. K., Kepner, J. L., Thomas, P. R., et al. (1998) · Journal of Clinical Oncology · doi:10.1200/jco.1998.16.5.1723 · Cited by 397 · see citing works
Packer, R. J., Sutton, L. N., Atkins, T. E., Radcliffe, J., Bunin, G. R., D’Angio, G. J., Siegel, K. R., & Schut, L. (1989) · Journal of neurosurgery · doi:10.3171/jns.1989.70.5.0707 · Cited by 350 · see citing works
Whole-brain irradiation and decline in intelligence: the influence of dose and age on IQ score.
Silber, J. H., Radcliffe, J., Peckham, V. C., Perilongo, G., Kishnani, P. S., Fridman, M., Goldwein, J. W., & Meadows, A. T. (1992) · Journal of Clinical Oncology · doi:10.1200/jco.1992.10.9.1390 · Cited by 341 · see citing works
Butler, R. W., & Copeland, D. R. (2002) · Journal of the International Neuropsychological Society · doi:10.1017/s1355617702811110 · Cited by 304 · see citing works
Self-citationMulhern, R. K., Palmer, S. L., Reddick, W. E., Glass, J. O., Kun, L. E., Taylor, J. S., Langston, J., & Gajjar, A. J. (2001) · Journal of Clinical Oncology · doi:10.1200/jco.2001.19.2.472 · Cited by 304 · see citing works
Ochs, J., Mulhern, R. K., Fairclough, D. C., Parvey, L. S., Whitaker, J. N., Ch'ien, L. T., Mauer, A., & Simone, J. V. (1991) · Journal of Clinical Oncology · doi:10.1200/jco.1991.9.1.145 · Cited by 283 · see citing works
Reddick, W. E., White, H. A., Glass, J. O., et al. (2003) · Cancer · doi:10.1002/cncr.11355 · Cited by 275 · see citing works
Factors Affecting Intellectual Outcome in Pediatric Brain Tumor Patients
Ellenberg, L., McComb, J. G., Siegel, S. E., & Stowe, S. M. (1987) · Neurosurgery · doi:10.1227/00006123-198711000-00006 · Cited by 273 · see citing works
Non-asbestos-related malignant mesothelioma. A review
Peterson, J. T., Greenberg, S. D., & Buffler, P. A. (1984) · Cancer · doi:10.1002/1097-0142(19840901)54:5 · Cited by 251 · see citing works
Mulhern, R. K., Fairclough, D. C., & Ochs, J. (1991) · Journal of Clinical Oncology · doi:10.1200/jco.1991.9.8.1348 · Cited by 248 · see citing works
Neuropsychological long-term sequelae after posterior fossa tumour resection during childhood
Steinlin, M. I. (2003) · Brain · doi:10.1093/brain/awg195 · Cited by 247 · see citing works
Moleski, M. (2000) · Archives of Clinical Neuropsychology · doi:10.1016/s0887-6177(99)00050-5 · Cited by 245 · see citing works
Mulhern, R. K., Hancock, J., Fairclough, D. L., et al. (1992) · Medical and Pediatric Oncology · doi:10.1002/mpo.2950200302 · Cited by 233 · see citing works
Long‐term sequelae after pediatric brain tumors: Their effect on disability and quality of life
Lannering, B., Márky, I., Lundberg, A., & Olsson, E. (1990) · Medical and Pediatric Oncology · doi:10.1002/mpo.2950180410 · Cited by 221 · see citing works
Ris, M. D., & Noll, R. B. (1994) · Journal of Clinical and Experimental Neuropsychology · doi:10.1080/01688639408402615 · Cited by 221 · see citing works
Late effects of treatment on the intelligence of children with posterior fossa tumors
Duffner, P. K., Cohen, M. E., & Thomas, P. (1983) · Cancer · doi:10.1002/1097-0142(19830115)51:2 · Cited by 220 · see citing works
Neuropsychological performance and quality of life of 10 year survivors of childhood medulloblastoma
Maddrey, A. M., Bergeron, J. A., Lombardo, E. R., McDonald, N., Mulne, A. F., Barenberg, P. D., & Bowers, D. C. (2005) · Journal of Neuro-Oncology · doi:10.1007/s11060-004-3009-z · Cited by 208 · see citing works
Beebe, D. W., Ris, M. D., Armstrong, F. D., et al. (2005) · Journal of Clinical Oncology · doi:10.1200/jco.2005.06.117 · Cited by 205 · see citing works
Adult-derived neural precursors transplanted into multiple regions in the adult brain
Herrera, D. G., García‐Verdugo, J. M., & Álvarez-Buylla, A. (1999) · Annals of Neurology · doi:10.1002/1531-8249(199912)46:6 · Cited by 204 · see citing works
Neurobehavioral effects of central nervous system prophylactic treatment of cancer in children
Fletcher, J. M., & Copeland, D. R. (1988) · Journal of Clinical and Experimental Neuropsychology · doi:10.1080/01688638808408255 · Cited by 202 · see citing works
Moleski, M. (2000) · Archives of Clinical Neuropsychology · doi:10.1093/arclin/15.7.603 · Cited by 200 · see citing works
Long-term sequelae in children after cerebellar astrocytoma surgery
Aarsen, F. K., Dongen, H. R. V., Paquier, P. F., van Mourik, M., & Catsman‐Berrevoets, C. E. (2004) · Neurology · doi:10.1212/01.wnl.0000120549.77188.36 · Cited by 199 · see citing works
Reimers, T. S., Ehrenfels, S., Mortensen, E. L., Schmiegelow, M., Sønderkær, S., Carstensen, H., Schmiegelow, K., & Müller, J. (2002) · Medical and Pediatric Oncology · doi:10.1002/mpo.10211 · Cited by 197 · see citing works
Butler, R. W., Hill, J. M., Steinherz, P. G., et al. (1994) · Journal of Clinical Oncology · doi:10.1200/jco.1994.12.12.2621 · Cited by 193 · see citing works
Self-citationNeuropsychological Sequelae of Childhood Cancer in Long-Term Survivors
Copeland, D. R., Fletcher, J. M., Pfefferbaum-Levine, B., Jaffe, N., Ried, H. L., & Maor, M. H. (1985) · PEDIATRICS · doi:10.1542/peds.75.4.745 · Cited by 189 · see citing works
Mulhern, R. K., Khan, R. B., Kaplan, S. L., Helton, S., Christensen, R., Bonner, M. J., Brown, R. T., Xiong, X., Wu, S., Gururangan, S., et al. (2004) · Journal of Clinical Oncology · doi:10.1200/jco.2004.04.128 · Cited by 189 · see citing works
COGNITIVE EFFECTS OF CRANIAL IRRADIATION IN LEUKAEMIA: A SURVEY AND META‐ANALYSIS
Cousens, P., Waters, B. G. H., Said, J., et al. (1988) · Journal of Child Psychology and Psychiatry · doi:10.1111/j.1469-7610.1988.tb00757.x · Cited by 182 · see citing works
Thompson, S. J., Leigh, L. D., Christensen, R., et al. (2001) · Journal of Clinical Oncology · doi:10.1200/jco.2001.19.6.1802 · Cited by 180 · see citing works
Palmer, S. L., Gajjar, A. J., Reddick, W. E., Glass, J. O., Kun, L. E., Wu, S., Xiong, X., & Mulhern, R. K. (2003) · Neuropsychology · doi:10.1037/0894-4105.17.4.548 · Cited by 180 · see citing works
Soni, S. S., Marten, G. W., Pitner, S. E., et al. (1975) · New England Journal of Medicine · doi:10.1056/nejm197507172930303 · Cited by 177 · see citing works
Neurocognitive Development of Children After a Cerebellar Tumor in Infancy: A Longitudinal Study
Copeland, D. R., deMoor, C., Moore, B. D., & Ater, J. L. (1999) · Journal of Clinical Oncology · doi:10.1200/jco.1999.17.11.3476 · Cited by 176 · see citing works
Rowland, J. H., Glidewell, O. J., Sibley, R. F., Holland, J. C., Tull, R., Berman, A. W., Brecher, M. L., Harris, M., Glicksman, A. S., & Forman, E. N. (1984) · Journal of Clinical Oncology · doi:10.1200/jco.1984.2.12.1327 · Cited by 176 · see citing works
Cavazzuti, V., Fischer, E. G., Welch, K., Belli, J. A., & Winston, K. R. (1983) · Journal of neurosurgery · doi:10.3171/jns.1983.59.3.0409 · Cited by 170 · see citing works
Neuropsychologic effects of chemotherapy on children with cancer: a longitudinal study.
Copeland, D. R., Moore, B. D., Francis, D. J., et al. (1996) · Journal of Clinical Oncology · doi:10.1200/jco.1996.14.10.2826 · Cited by 169 · see citing works
Waber, D. P., Carpentieri, S. C., Klar, N. S., Silverman, L. B., Schwenn, M. R., Hurwitz, C. A., Mullenix, P. J., Tarbell, N. J., & Sallan, S. E. (2000) · The American journal of pediatric hematology/oncology · doi:10.1097/00043426-200005000-00004 · Cited by 166 · see citing works
Buizer, A. I., de Sonneville, L. M. J., van den Heuvel‐Eibrink, M. M., & Veerman, A. J. P. (2005) · Pediatric Blood & Cancer · doi:10.1002/pbc.20397 · Cited by 156 · see citing works
von der Weid, N., Mosimann, I., Hirt, A., et al. (2003) · European Journal of Cancer · doi:10.1016/s0959-8049(02)00260-5 · Cited by 155 · see citing works
Medulloblastoma in childhood: progressive intellectual deterioration
Hoppe-Hirsch, E., Rénier, D., Lellouch‐Tubiana, A., Sainte‐Rose, C., Pierre‐Kahn, A., & Hirsch, J. F. (1990) · Child s Nervous System · doi:10.1007/bf00307922 · Cited by 153 · see citing works
Brown, R. T., Madan‐Swain, A., Walco, G. A., et al. (1998) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/23.5.333 · Cited by 148 · see citing works
Attention and Memory Functioning Among Pediatric Patients with Medulloblastoma
Reeves, C. B., Palmer, S. L., Reddick, W. E., Merchant, T. E., Buchanan, G. M., Gajjar, A. J., & Mulhern, R. K. (2005) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/jsj019 · Cited by 143 · see citing works
Atypical white matter volume development in children following craniospinal irradiation
Reddick, W. E., Glass, J. O., Palmer, S. L., Wu, S., Gajjar, A. J., Langston, J. W., Kun, L. E., Xiong, X., & Mulhern, R. K. (2005) · Neuro-Oncology · doi:10.1215/s1152851704000079 · Cited by 135 · see citing works
Long-term psychological effects in children treated for intracranial tumors
Jannoun, L., & Bloom, H. J. G. (1990) · International Journal of Radiation Oncology*Biology*Physics · doi:10.1016/0360-3016(90)90393-x · Cited by 129 · see citing works
Mulhern, R. K., Wasserman, A. L., Fairclough, D. C., et al. (1988) · Journal of Clinical Oncology · doi:10.1200/jco.1988.6.2.315 · Cited by 124 · see citing works
Espy, K. A. (2001) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/26.1.1 · Cited by 124 · see citing works
Cognitive and Academic Functioning in Survivors of Pediatric Bone Marrow Transplantation
Phipps, S., Dunavant, M., Srivastava, D. K., et al. (2000) · Journal of Clinical Oncology · doi:10.1200/jco.2000.18.5.1004 · Cited by 118 · see citing works
Factors associated with IQ scores in long-term survivors of childhood acute lymphoblastic leukemia
Robison, L. L., Meadows, A. T., Nesbit, M. E., et al. (1984) · Journal of Pediatric Hematology/Oncology · doi:10.1097/00043426-198406020-00001 · Cited by 115 · see citing works
Mulhern, R. K., White, H. A., Glass, J. O., Kun, L. E., Leigh, L., Thompson, S. J., & Reddick, W. E. (2004) · Journal of the International Neuropsychological Society · doi:10.1017/s135561770410204x · Cited by 114 · see citing works
Rj, P., Savino, P. J., Lt, B., et al. (1983) · PubMed · Cited by 110 · see citing works
Neuropsychological Effects of Childhood Cancer Treatment
Copeland, D. R., Dowell, R. E., Fletcher, J. M., Bordeaux, J., Sullivan, M. P., Jaffe, N., Frankel, L. S., Ried, H. L., & Cangır, A. (1988) · Journal of Child Neurology · doi:10.1177/088307388800300113 · Cited by 98 · see citing works
Packer, R. J., Sposto, R., Atkins, T. E., Sutton, L. N., Bruce, D. A., Siegel, K. R., RORKE, L. B., Littman, P. A., & Schut, L. (1987) · Pediatric Neurosurgery · doi:10.1159/000120325 · Cited by 96 · see citing works
Late effects in survivors of infant leukemia
Leung, W. H., Hudson, M. M., Zhu, Y., Rivera, G. K., Ribeiro, R., Sandlund, J. T., Bowman, L., We, E., Kun, L. E., & Pui, C.-H. (2000) · Leukemia · doi:10.1038/sj.leu.2401818 · Cited by 88 · see citing works
Multiattribute approach to the assessment of health-related quality of life: Health utilities index
Feeny, D., Furlong, W. J., & Barr, R. D. (1998) · Medical and Pediatric Oncology · doi:10.1002/(sici)1096-911x(1998)30:1+ · Cited by 83 · see citing works
Reddick, W. E., Mulhern, R. K., Elkin, T. D., et al. (1998) · Magnetic Resonance Imaging · doi:10.1016/s0730-725x(98)00014-9 · Cited by 82 · see citing works
Moore, B. D., Ater, J. L., & Copeland, D. R. (1992) · Journal of Child Neurology · doi:10.1177/088307389200700308 · Cited by 71 · see citing works
Lockwood, K. A. (1999) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/24.1.55 · Cited by 71 · see citing works
Neuropsychological Functioning after Surgery in Children Treated for Brain Tumor
Carpentieri, S. C., Waber, D. P., Pomeroy, S. L., et al. (2003) · Neurosurgery · doi:10.1227/01.neu.0000064804.00766.62 · Cited by 62 · see citing works
Waber, D. P., Gioia, G., Paccia, J. M., et al. (1990) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/15.1.105 · Cited by 62 · see citing works
Riva, D., Pantaleoni, C., Milani, N., et al. (1989) · Child s Nervous System · doi:10.1007/bf00571120 · Cited by 61 · see citing works
Butler, R. W., & Copeland, D. R. (1993) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/18.3.319 · Cited by 61 · see citing works
Self-citationRadiation Injury of the Nervous System.
Olson, J. J. (1992) · Neurosurgery · doi:10.1097/00006123-199203000-00030 · Cited by 59 · see citing works
DeLong, R. G., Friedman, H. T., Friedman, N. E., et al. (1992) · Journal of Child Neurology · doi:10.1177/088307389200700425 · Cited by 57 · see citing works
Mulhern, R. K., Ochs, J., Fairclough, D. C., et al. (1987) · Journal of Clinical Oncology · doi:10.1200/jco.1987.5.6.933 · Cited by 54 · see citing works
Attentional ability among survivors of leukaemia
Rodgers, J., Horrocks, J., Britton, P. G., & Kernahan, J. (1999) · Archives of Disease in Childhood · doi:10.1136/adc.80.4.318 · Cited by 51 · see citing works
Neuropsychological Test Performance of Pediatric Cancer Patients at Diagnosis and One Year Later
Copeland, D. R., Dowell, R. E., Fletcher, J. M., et al. (1988) · Journal of Pediatric Psychology · doi:10.1093/jpepsy/13.2.183 · Cited by 51 · see citing works
Tamaroff, M. H., Miller, D. R., Murphy, M. L., et al. (1982) · The Journal of Pediatrics · doi:10.1016/s0022-3476(82)80694-x · Cited by 51 · see citing works
Chiasmatic Gliomas of Childhood
Packer, R. J., Savino, P. J., Bilaniuk, L. T., et al. (1983) · Pediatric Neurosurgery · doi:10.1159/000120141 · Cited by 35 · see citing works
Meyer, E. A., & Kieran, M. W. (2002) · Psycho-Oncology · doi:10.1002/pon.553 · Cited by 33 · see citing works
Eisbruch, A., Blick, M. B., Evinger-Hodges, M. J., Beran, M., Andersson, B. A. R., Gutterman, J. U., & Kurzrock, R. (1988) · Cancer · doi:10.1002/1097-0142(19880915)62:6 · Cited by 30 · see citing works
Visual attention in long-term survivors of leukemia receiving cranial radiation therapy
Schatz, J. C., Kramer, J. H., Ablin, A. R., & Matthay, K. K. (2004) · Journal of the International Neuropsychological Society · doi:10.1017/s1355617704102075 · Cited by 27 · see citing works
NEUROPSYCHOLOGICAL OUTCOME OF CHILDREN AFTER RADIOTHERAPY FOR INTRACRANIAL TUMOURS
García‐Peréz, A., Narbona-García, J., Sierrasesúmaga, L., et al. (1993) · Developmental Medicine & Child Neurology · doi:10.1111/j.1469-8749.1993.tb11615.x · Cited by 26 · see citing works
The Effects of Childhood Cancer and Its Treatment on Two Objective Measures of Psychological..
Butler, R. W., Rizzi, L. P., & Bandilla, E. B. (1999) · Children s Health Care · doi:10.1207/s15326888chc2804_3 · Cited by 13 · see citing works
Self-citationNeuropsychological Effects of Stimulant Medication on Children’s Learning and Behavior
Brown, R. T., Dreelin, E. D., & Dingle, A. D. (1997) · Critical issues in neuropsychology · doi:10.1007/978-1-4757-5351-6_27 · Cited by 10 · see citing works
Flagged first, then by citations
Cited by
Sorted by citations
Space Radiation: The number one risk to astronaut health beyond low earth orbit
Chancellor, J., Scott, G., & Sutton, J. (2014) · Life · doi:10.3390/life4030491 · Cited by 455 · see citing works
Space radiation risks to the central nervous system
Cucinotta, F. A., Alp, M., Sulzman, F. M., & Wang, M. (2014) · Life Sciences in Space Research · doi:10.1016/j.lssr.2014.06.003 · Cited by 262 · see citing works
Iyer, N. S., Balsamo, L. M., Bracken, M. B., & Kadan-Lottick, N. S. (2015) · Blood · doi:10.1182/blood-2015-02-627414 · Cited by 194 · see citing works
Sluggish cognitive tempo in survivors of pediatric brain tumors
Willard, V. W., Hardy, K. K., Allen, T. M., Hwang, E. I., Gururangan, S., Hostetter, S. A., & Bonner, M. J. (2013) · Journal of Neuro-Oncology · doi:10.1007/s11060-013-1149-8 · Cited by 36 · see citing works
- Authors
- Butler, R. W., & Haser, J. K.
- Affiliations
- Oregon Health & Science University (US)
- Corresponding author
- Butler, Robert W.
- Venue
- Mental Retardation and Developmental Disabilities Research Reviews
- Publisher
- Wiley
- Published
- 2006-01
- Volume
- 12
- Issue
- 3
- Pages
- 184-191
- ISSN
- 1080-4013 (ISSN-L)
- 1098-2779
- OpenAlex
- W2045533008
- Cited by
- 203
- References
- 78
- Citations by year
- 2026: 4 · 2025: 5 · 2024: 6 · 2023: 4 · 2022: 2 · 2021: 4 · 2020: 5 · 2019: 9 · 2018: 6 · 2017: 10 · 2016: 13 · 2015: 18 · 2014: 18 · 2013: 13 · 2012: 15
- FWCI
- 1.83
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Mental Retardation and Developmental Disabilities Research Reviews (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Cancer Institute (R01CA083936, R01 CA83936)
- Topics
- Health Sciences › Medicine › Pediatrics, Perinatology and Child Health › Childhood Cancer Survivors' Quality of Life
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Cancer-related cognitive impairment studies
- Health Sciences › Medicine › Public Health, Environmental and Occupational Health › Acute Lymphoblastic Leukemia research
- Keywords
- neurocognitive effects, childhood cancer, central nervous system cancer, pediatric leukemia, brain tumors, cancer survivors, intelligence, academic difficulties, cognitive remediation, neuropsychology, cognitive neuroscience, neuroimaging
- MeSH terms
- Antineoplastic Agents, Brain Neoplasms, Child, Developmental Disabilities, Cognition Disorders, Combined Modality Therapy, Humans, Injections, Spinal, Intellectual Disability, Methotrexate, Cranial Irradiation, Precursor Cell Lymphoblastic Leukemia-Lymphoma
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review