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Why is toilet training occurring at older ages? A study of factors associated with later training
CLINICAL AND LABORATORY OBSERVATIONS
WHY IS TOILET TRAINING OCCURRING AT OLDER AGES? A STUDY OF FACTORS ASSOCIATED WITH LATER TRAINING NATHAN J. BLUM, MD, BRUCE TAUBMAN, MD, AND NICOLE NEMETH, MD
Recent studies suggest that children are completing toilet training much later than the preceding generation. Our objective was to identify factors associated with later toilet training. Children between 17 and 19 months of age (n = 406) were enrolled in the study. At enrollment, parents completed the Parenting Stress Index and the Receptive-Expressive Emergent Language Scale. Follow-up parent interviews were conducted every 2 to 3 months until children completed daytime toilet training. Information obtained at follow-up interviews included steps parents were taking to toilet train their child, child toilet training behaviors, presence and frequency of constipation, birth of a sibling, and child care arrangements. In a stepwise linear regression model predicting age at completion of toilet training, 3 factors were consistently associated with later training: initiation of toilet training at an older age, presence of stool toileting refusal, and presence of frequent constipation. Models including these variables explained 25% to 39% of the variance in age at completion of toilet training. In conclusion, a later age at initiation of toilet training, stool toileting refusal, and constipation may explain some of the trend toward completion of toilet training at later ages. (J Pediatr 2004;145:107–11)
oilet training is occurring at older ages than it did in the past. For example, in a study of more than 1000 children trained in the 1950s, Brazelton1 found that the mean age at completion of daytime toilet training was 28.5 months, and >97% had achieved this milestone by 36 months of age. A study of 266 children trained during the mid 1980s found a mean age of completion of toilet training between 25 and 27 months of age.2 However, recent studies suggest that only 40% to 60% of children are completing training by 36 months of age.3,4 This late toilet training is potentially concerning because it causes stress for some families and leads to more diaper changing in day care settings, which increases the chance of spreading infectious diarrhea and hepatitis A in these facilities.5,6 See editorial, p 12. The factors that are associated with late toilet training are not clear. Previous studies suggest that child factors (eg, sex, developmental status, temperament), parent or family factors (eg, race, presence of siblings, parental education, socioeconomic status, single parenthood), and factors occurring during toilet training (eg, age at initiation of training, constipation, stool toileting refusal) influence the age at completion of training.3,4,7 However, with the exception of female sex, which is consistently associated with earlier From the Division of Child Development and Rehabilitation and the Ditraining,3,8,9 many of these factors have been investigated in only single studies, and there vision of Gastroenterology, Children’s are no studies that have looked at all of these factors prospectively. Hospital of Philadelphia, University of Pennsylvania, School of Medicine, In this study, we investigated the relative role of child characteristics, characteristics Philadelphia, Pennsylvania; and Pediatof the care-giving environment, and a variety of experiences during toilet training on the ric Physicians of Burlington County, age at completion of toilet training. Since it was likely that child characteristics had not New Jersey. Supported in part by a grant from the changed dramatically in the last 30 to 50 years, we hypothesized that experiences during Maternal and Child Health Bureau #6 toilet training and perhaps aspects of the care-giving environment would be the most T77 MC 00012-07 2. important factors in explaining variation in the age at completion of toilet training and may Submitted for publication Oct 15, 2003; last revision received Dec 17, 2003; help to explain the trend toward later toilet training.
T
METHODS Sample The sample and design of this study have been described previously.10,11 Families of 408 consecutive 17- to 19-month-old children from the private pediatric practice of one of PSI
Parenting Stress Index
REEL
Receptive-Expressive Emergent Language Scale
accepted Feb 17, 2004. Reprint requests: Nathan J. Blum, MD, Children’s Seashore House of Children’s Hospital of Philadelphia, 3405 Civic Center Blvd, Philadelphia, PA 19104. E-mail: [email protected]. edu. 0022-3476/$ - see front matter Copyright ª 2004 Elsevier Inc. All rights reserved. 10.1016/j.jpeds.2004.02.022
107
the authors were asked to participate in a study designed to investigate factors related to age of completion of toilet training and to study a previously described intervention, praising children for defecating and not referring to stool in negative terms, which was designed to decrease the frequency of stool toileting refusal, but was not effective.10 Parents of 406 children gave written informed consent to participate in the study. Children with global developmental delays or structural abnormalities of the spinal cord, genitourinary tract, or gastrointestinal tract were excluded. Overall, 378 (93%) were followed until they completed daytime toilet training and are the subject of this article. The pediatric practice is in the suburbs of a major metropolitan area and serves predominately middle and upper-middle class families. More than 90% of the families are white, and the mean ± SD Hollingshead score12 was 52.4 ± 10.8, which is near the top of social strata IV of the 5-category index. The study was approved by the Institutional Review Board of The Children’s Hospital of Philadelphia.
defined the age of intensive toilet training as the age at which parents asked their child to sit on the toilet or potty more than 3 times per day. Late toilet training was defined as toilet training occurring after 42 months of age, as <1% of children in Brazelton’s study of toilet training in the 1950s were daytime-trained after 42 months of age.1 Children were coded as being frequently constipated if they were treated by the pediatrician for constipation or if parents stated that their child was constipated more than once per week at any followup phone call or about once per week at 2 or more follow-up interviews. Daytime toilet training was scored as completed when parents reported that the child wears underwear during the day and urinates and defecates in the toilet or potty with fewer than 4 urine accidents per week and 2 or fewer episodes of fecal soiling per month. Stool toileting refusal was scored as occurring when a child refused to defecate in the toilet or potty for longer than 1 month after meeting the criteria for daytime toilet training for urine.
Parenting Stress Index Measures and Procedures We assessed the relative contribution of child characteristics, aspects of the care-giving environment, and experiences during toilet training on age at completion of training. At enrollment, child characteristics such as temperament and language development were assessed with the Parenting Stress Index (PSI)13,14 and Receptive-Expressive Emergent Language Scale (REEL),15 respectively. These instruments are described further below. The PSI also allowed assessment of parental stress levels at enrollment. Additional parent and family factors and factors occurring during toilet training were assessed at semistructured interviews that were conducted by telephone every 2 to 3 months until the parents reported that child had completed daytime toilet training at 2 consecutive interviews.
The PSI13,14 is a 120-item rating scale designed for parents of children under 12 years of age. Normal values are available on the basis of administration to more than 2600 individuals. The child domain assesses 4 aspects of the child’s temperament: distractibility/hyperactivity, adaptability, mood, demandingness, and 2 measures that assess the degree to which the child matches the parent expectations and is a source of positive reinforcement for the parent. The parent domain assesses 7 sources of stress, including parent competence, isolation, attachment, health, role restriction, depression, and spouse relationships. For 1- to 2-year-old children the mean (SD) of the child domain stress score in the standardization sample was 98 (20) and the mean for the parent domain stress score was 127 (26).13
Receptive-expressive Emergent Language Scale Follow-up Semistructured Interviews Information obtained at follow-up interviews included whether parents asked the child to sit on the potty in the time since the last interview, and, if yes, how many times per day; whether the child was urinating on the toilet or potty almost always, sometimes, or never, and, if almost always, how many accidents per week the child had; whether the child was having bowel movements on the toilet or potty almost always, sometimes or never, and, if almost always, how many accidents the child had in the past month. Separate questions were asked about hard bowel movements, painful bowel movements, and hiding while having bowel movements. For these symptoms parents were asked if, since the last interview, these symptoms occurred never, once or twice, about once per week, or more than once per week. In addition, we obtained information about child care arrangements and birth of a sibling at each interview. We defined the age of initiation of toilet training as the age at which parents took out a potty-chair and began discussing some aspect of toilet training with the child. We 108
Blum, Taubman, and Nemeth
The REEL15 is a parent report measure designed to assess language development in children from birth to 36 months of age. The REEL provides language scores in 2- to 3month age intervals, which are expressed as developmental quotients (REEL language age/chronological age 3 100). Test-retest reliability over a 3-week interval was 0.7115. National normal values for the REEL are not available, but in three validity studies, children’s mean language ages have been found to be at or slightly above their chronological age.15
Statistics Statistical analyses were performed with the use of the Statistical Package for the Social Sciences (SPSS version 9.0). Means for continuous variables in the late toilet training group were compared with the rest of the sample through the use of the t test for independent variables. Dichotomous variables were compared between late toilet trainers and the rest of the sample by means of the v2 statistic. To adjust for the multiple comparisons, we used a Bonferroni correction in which we considered only P values <.004 to be statistically significant. The Journal of Pediatrics July 2004
Table I. Child and family factors in children who toilet train before and after 42 months of age Training age #42 mo n = 318
> 42 mo n = 60
P value
52.6 ± 10.9 20.6 ± 2.3 28.0 ± 5.1 49.7% 94.4 ± 15.6 108 ± 19 132 ± 20 17.9% 55.3% 26.2% 13.2% 15.2% 66.1%
50.6 ± 10.2 22.3 ± 3.5 31.9 ± 6.6 65% 97.1 ± 14.6 113 ± 22 123 ± 21 56.7% 50.0% 38.5% 41.7% 8.3% 86.7%
> .10 < .001y < .001y .034 > .10 .10 .002y < .001y > .10 .07 < .001y > .10 .001y
Mean Hollingshead score Mean age at initiation of toilet training (mo)* Mean age at initiation of intensive toilet training (mo)*z % Boys* PSI, mean child stress score PSI, mean parent stress score* REEL language quotient* % With stool toileting refusal* % With older sibling* % With younger sibling % Frequently constipated* % In day care throughout study % Hide during training* *Variables included in linear regression models described in Tables II and III. yStatistically significant, P <.004 (Bonferroni adjustment). zBased on 297 subjects who met criteria for intensive toilet training.
P values <.10 but >.004 are discussed as possible trends. A stepwise multiple linear regression procedure was used to investigate the independent contribution of factors found to be important in the above analyses in predicting the age at completion of toilet training. For this analysis, a value of P < .05 was considered to be statistically significant.
RESULTS Children in this sample completed daytime toilet training at a mean of 36.8 ± 6.1 months (range, 22 to 54 months). Sixty of the 378 children (16%) did not complete daytime toilet training until after 42 months and were defined as late toilet trainers. There were no differences between the control group and intervention group for any of the child, family, or initiation of toilet training variables shown in Table I for those who trained by 42 months of age or in those who trained after 42 months (data not shown). Thus, for analyses of the variables shown in Table I, we combined the intervention and control groups. However, the group that trained by 42 months of age did have a higher percentage of individuals in the intervention group than the group that trained after 42 months (54.1% vs 38.3%; P = .034). Thus, we did include membership in the intervention versus control group in the regression model of factors that predict late toilet training. As shown in Table I, parents of later toilet trainers initiated toilet training at an older age than did parents of those who trained earlier; 278 families met our criteria for intensive toilet training at some point during the toilet training process. For these children, later age at initiation of intensive toilet training was also associated with completion of training after 42 months of age. In addition, the later trainers were more likely to have stool toileting refusal, to hide when defecating, to be frequently constipated, and to have a lower language score at 18 months. There was also a possible trend Why is Toilet Training Occurring at Older Ages? A Study of Factors Associated with Later Training
toward the later trainers being more likely to be boys, to have a higher score of the parent domain of the PSI, to hide when defecating before being toilet trained, and to be in the control group. We investigated the ability of these 10 factors (9 noted by asterisks in Table I plus being in the intervention group) to predict age at completion of toilet training in two linear regression models. The first model included all the children in the sample (Table II) and the second model included only those children whose families met the criteria for intensive toilet training (Table III). For the entire sample, the 7 variables shown in Table II explained 33% of the variance in age at completion of training. For those who met the criteria for intensive toilet training, the 6 variables shown in Table III explained 44% of the variance. In both models, 3 of the variables, the occurrence of stool toileting refusal, the occurrence of frequent constipation, and either the age at initiation of toilet training or the age at initiation of intensive toilet training were the strongest predictors. In the model shown in Table II, the 3 variables alone would explain 25% of the variance, and in the model shown in Table III, the 3 variables would explain 39% of the variance in the age at completion of toilet training.
DISCUSSION For many children today, toilet training is being completed much later than in the past. We found that three factors consistently explained a significant portion of the variance in age at completion of toilet training: age at initiation of toilet training (or intensive toilet training), the occurrence of stool toileting refusal, and the occurrence of frequent constipation. The relatively large effect of these three variables in our study, combined with epidemiologic data from other sources, suggests that these variables may contribute to 109
Table II. Linear regression model predicting age at completion of toilet training for all children in sample Factors*
Standardized regression coefficient
P value
Overall P value
Overall R2
Stool toileting refusal Age initiation of toilet training Frequently constipated Sex Hides during training Has younger sibling REEL language quotient
0.342 0.173 0.170 0.132 0.148 0.135 0.116
< .001 < .001 < .001 .004 .001 .002 .011
< .001
0.329
*Age at initiation of intensive training was not included in this model because some families never reported meeting the criteria for intensive toilet training.
Table III. Linear regression model predicting age at completion of toilet training for 278 children who met criteria for intensive toilet training Factor
Standardized regression coefficient
P value
Overall P value
Overall R2
Age initiation intensive toilet training Stool toileting refusal Frequently constipated Has younger sibling Hides during training In control group
0.414 0.359 0.175 0.133 0.128 0.094
< .001 < .001 < .001 .003 .005 .040
< .001
0.444
the trend toward later completion of toilet training that has been seen over the last 30 to 50 years. For example, studies that have investigated trends in the age at initiation of toilet training suggest that toilet training is being initiated later than it was 30 years ago.8,16,17 In a survey of parents in Iowa in 1970, >95% expected to begin toilet training before 24 months of age.18 In a survey of parents in Minnesota in 1985, 73% began training before 29 months of age,2 and in a 1996 survey of parents from the greater Milwaukee metropolitan area, toilet training had not started in 35% of 30- to 34-month-old children.3 The reasons that parents now initiate training at older ages are not known. Berk and Friman16 have suggested that it is related to widespread dissemination of information, suggesting that early training does not lead to earlier completion of training and the ready availability of disposable diapers. It has also been suggested that parents may have difficulty judging when children are ready to train.11 For example, a recent study of when children achieved 11 different readiness skills found that the earliest achieved readiness skill (eg, stays bowel movement–free overnight) occurred at a median of 22 months in girls and almost 25 months in boys.19 The skill that was achieved the latest (eg, pulls training pants or underwear up by oneself) was not achieved until a median of 29.5 months in girls and 33.5 months in boys.19 Given the large age range over which these skills occur, it would not be surprising if parents have a difficult time judging when their child is ready to toilet train or alternatively decided to wait until the child has achieved all the readiness skills. 110
Blum, Taubman, and Nemeth
Our study supports earlier reports that stool toileting refusal is associated with delayed toilet training as more than half of the children who did not train until after 42 months had stool toileting refusal.4,20 Stool toileting refusal has been associated with constipation,20,21 but in our study’s multiple regression model, both frequent constipation and stool toileting refusal made an independent contribution to predicting age at completion of toilet training. Although changes in these factors over time are not well studied, some data would suggest that these factors may also contribute to the trend toward later training. For example, Brazelton found that >90% of children trained for bowel first or bowel and bladder at the same time.1 A longitudinal study of healthy Swiss children from 1955 to 1976 found that >95% of 3-yearolds were reported to be trained for bowel movements, whereas <2% had daytime bladder control and were not trained for bowel movements.22 Not all of the children who obtained bladder control before achieving toilet training for bowel movements would meet our criteria for stool toileting refusal, but it is clear that those who train at the same time or train for bowel movements first would not. Thus, the maximum possible incidence of stool toileting refusal in previous studies is 2% to 10%, compared with the 20% to 25% incidence that we have found in this and another recent study.4 The reasons for the increase in this specific type of resistance to toilet training are not known, but it appears to be increasing and contributing significantly to the trend toward later completion of toilet training. Trends related to constipation are difficult to evaluate because of huge differences in the incidence, based on the The Journal of Pediatrics July 2004
definition and method of reporting. However, Sonnenberg and Koch23 found that although the overall rate of physician visits for constipation was unchanged between 1958 and 1986, there was a 2-fold increase in physician visits for constipation in patients 0 to 9 years of age, suggesting that constipation in the pediatric age group is increasing. Others have also reported very high rates of constipation in children of toilet training age.24 Additional factors that we or others have found to be associated with later toilet training such as male sex, white race, not living in a single-parent family, and some temperament factors are either very unlikely to have changed significantly in the past several years or have not changed in the direction that would explain the trend toward later training. For example, there are more single-parent families today than 50 years ago, but children in single-parent families have been found to train earlier.3 The results in this study should be considered in the context of the following limitations. The results apply to a primarily white, suburban, upper middle-class population. Because of the homogeneity of the sample, the effect of race and being a single parent could not be investigated in this study, and the factors influencing toilet training are likely to be different in other populations.25,26 All of the information in this study was collected by parent report. We attempted to minimize recall bias by interviewing parents every 2 to 3 months, but our results were still dependent on the parent’s recall and report of their toilet training practices and results. Despite these limitations, our study identifies three factors that are highly associated with an older age at completion of toilet training. In addition, there is evidence to suggest these three factors, age at initiation of toilet training, the development of stool toileting refusal, and constipation, have changed over the last 30 to 50 years in ways that could contribute to the trend toward later training. Further studies will be needed to determine whether interventions targeting these variables result in a decreased incidence of late toilet training.
REFERENCES 1. Brazelton TB. A child-oriented approach to toilet training. Pediatrics 1962;29:121-8. 2. Seim HC. Toilet training in first children. J Fam Pract 1989;29:633-6. 3. Schum TR, McAuliffe TL, Simms MD, Walter JA, Lewis M, Pupp R. Factors associated with toilet training in the 1990s. Ambulat Pediatr 2001;1:79-86. 4. Taubman B. Toilet training and toileting refusal for stool only: a prospective study. Pediatrics 1997;99:54-8.
Why is Toilet Training Occurring at Older Ages? A Study of Factors Associated with Later Training
5. Pickering LK, Bartlett AV, Woodward WE. Acute infectious diarrhea among children in day care: epidemiology and control. Rev Infect Dis 1986;8:539-47. 6. Hadler SC, McFarland L. Hepatitis in day care centers: epidemiology and prevention. Rev Infect Dis 1986;8:548-57. 7. Schonwald A, Sherritt L, Stadtler A, Frazer C. Factors associated with difficult toilet training [abstract]. J Dev Behav Pediatr 2001;22:344-5. 8. Martin JA, King DR, Maccoby EE, Jacklin CN. Secular trends and individual differences in toilet-training progress. J Pediatr Psychol 1984;9:457-67. 9. Bloom DA, Seeley WM, Ritchey ML, McGuire EJ. Toilet habits and continence in children: an opportunity sampling in search of normal parameters. J Urol 1993;149:1087-90. 10. Taubman B, Blum NJ, Nemeth N. Stool toileting refusal: a prospective intervention targeting parental behavior. Arch Pediatr Adolesc Med 2003;157:1193–6. 11. Blum NJ, Taubman B, Nemeth N. Relationship between age at initiation of toilet training and duration of toilet training: a prospective study. Pediatrics 2003;111:810-4. 12. Hollingshead AB. Four factor index of social status. New Haven, Conn: Yale University; 1975. 13. Abidin RR. Parenting Stress Index professional manual. 3rd edition. Odessa, Fla: Psychological Assessment Resources; 1995. 14. Loyd BH, Abidin RR. Revision of the Parenting Stress Index. J Pediatr Psychol 1985;10:169-77. 15. Bzoch KR, League R. Assessing language skills in infancy: a handbook for the multi-dimensional analysis of emergent language. Baltimore, Md: University Park Press; 1980. 16. Berk LB, Friman PC. Epidemiologic aspects of toilet training. Clin Pediatr 1990;29:278-82. 17. Bakker E, Wyndaele JJ. Changes in the toilet training of children during the last 60 years: the cause of an increase in lower urinary tract dysfunction? BJU Int 2000;86:248-52. 18. Stehbens JA, Silber DL. Parental expectations in toilet training. Pediatrics 1971;48:451-4. 19. Schum TR, Kolb TM, McAuliffe, Simms MD, Underhill RL, Lewis M. Sequential acquisition of toilet-training skills: a descriptive study of gender and age differences in normal children. Pediatrics 2002;109:e48. 20. Blum NJ, Taubman B, Osborne ML. Behavioral characteristics of children with stool toileting refusal. Pediatrics 1997;99:50-3. 21. Taubman B, Buzby M. Overflow encopresis and stool toileting refusal during toilet training: a prospective study on the effect of therapeutic efficacy. J Pediatr 1997;131:768-71. 22. Largo RH, Stutzle W. Longitudinal study of bowel and bladder control by day and at night in the first six years of life, I: epidemiology and interrelations between bowel and bladder control. Dev Med Child Neurol 1977;19:598-606. 23. Sonnenberg A, Koch TR. Physician visits in the United States for constipation: 1958 to 1986. Dig Dis Sci 1989;34:606-11. 24. Issenman RM, Filmer RB, Gorski PA. A review of bowel and bladder control development in children: how gastrointestinal and urologic conditions relate to problems in toilet training. Pediatrics 1999;103:1346-52. 25. Luxem M, Christophersen E. Behavioral toilet training in early childhood: research, practice, and implications. J Dev Behav Pediatr 1994;15:370-8. 26. deVries MW, deVries MR. Cultural relativity of toilet training readiness: a perspective from East Africa. Pediatrics 1977;60:170-7.
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WHY IS TOILET TRAINING OCCURRING AT OLDER AGES? A STUDY OF FACTORS ASSOCIATED WITH LATER TRAINING NATHAN J. BLUM, MD, BRUCE TAUBMAN, MD, AND NICOLE NEMETH, MD
Recent studies suggest that children are completing toilet training much later than the preceding generation. Our objective was to identify factors associated with later toilet training. Children between 17 and 19 months of age (n = 406) were enrolled in the study. At enrollment, parents completed the Parenting Stress Index and the Receptive-Expressive Emergent Language Scale. Follow-up parent interviews were conducted every 2 to 3 months until children completed daytime toilet training. Information obtained at follow-up interviews included steps parents were taking to toilet train their child, child toilet training behaviors, presence and frequency of constipation, birth of a sibling, and child care arrangements. In a stepwise linear regression model predicting age at completion of toilet training, 3 factors were consistently associated with later training: initiation of toilet training at an older age, presence of stool toileting refusal, and presence of frequent constipation. Models including these variables explained 25% to 39% of the variance in age at completion of toilet training. In conclusion, a later age at initiation of toilet training, stool toileting refusal, and constipation may explain some of the trend toward completion of toilet training at later ages. (J Pediatr 2004;145:107–11)
oilet training is occurring at older ages than it did in the past. For example, in a study of more than 1000 children trained in the 1950s, Brazelton1 found that the mean age at completion of daytime toilet training was 28.5 months, and >97% had achieved this milestone by 36 months of age. A study of 266 children trained during the mid 1980s found a mean age of completion of toilet training between 25 and 27 months of age.2 However, recent studies suggest that only 40% to 60% of children are completing training by 36 months of age.3,4 This late toilet training is potentially concerning because it causes stress for some families and leads to more diaper changing in day care settings, which increases the chance of spreading infectious diarrhea and hepatitis A in these facilities.5,6 See editorial, p 12. The factors that are associated with late toilet training are not clear. Previous studies suggest that child factors (eg, sex, developmental status, temperament), parent or family factors (eg, race, presence of siblings, parental education, socioeconomic status, single parenthood), and factors occurring during toilet training (eg, age at initiation of training, constipation, stool toileting refusal) influence the age at completion of training.3,4,7 However, with the exception of female sex, which is consistently associated with earlier From the Division of Child Development and Rehabilitation and the Ditraining,3,8,9 many of these factors have been investigated in only single studies, and there vision of Gastroenterology, Children’s are no studies that have looked at all of these factors prospectively. Hospital of Philadelphia, University of Pennsylvania, School of Medicine, In this study, we investigated the relative role of child characteristics, characteristics Philadelphia, Pennsylvania; and Pediatof the care-giving environment, and a variety of experiences during toilet training on the ric Physicians of Burlington County, age at completion of toilet training. Since it was likely that child characteristics had not New Jersey. Supported in part by a grant from the changed dramatically in the last 30 to 50 years, we hypothesized that experiences during Maternal and Child Health Bureau #6 toilet training and perhaps aspects of the care-giving environment would be the most T77 MC 00012-07 2. important factors in explaining variation in the age at completion of toilet training and may Submitted for publication Oct 15, 2003; last revision received Dec 17, 2003; help to explain the trend toward later toilet training.
T
METHODS Sample The sample and design of this study have been described previously.10,11 Families of 408 consecutive 17- to 19-month-old children from the private pediatric practice of one of PSI
Parenting Stress Index
REEL
Receptive-Expressive Emergent Language Scale
accepted Feb 17, 2004. Reprint requests: Nathan J. Blum, MD, Children’s Seashore House of Children’s Hospital of Philadelphia, 3405 Civic Center Blvd, Philadelphia, PA 19104. E-mail: [email protected]. edu. 0022-3476/$ - see front matter Copyright ª 2004 Elsevier Inc. All rights reserved. 10.1016/j.jpeds.2004.02.022
107
the authors were asked to participate in a study designed to investigate factors related to age of completion of toilet training and to study a previously described intervention, praising children for defecating and not referring to stool in negative terms, which was designed to decrease the frequency of stool toileting refusal, but was not effective.10 Parents of 406 children gave written informed consent to participate in the study. Children with global developmental delays or structural abnormalities of the spinal cord, genitourinary tract, or gastrointestinal tract were excluded. Overall, 378 (93%) were followed until they completed daytime toilet training and are the subject of this article. The pediatric practice is in the suburbs of a major metropolitan area and serves predominately middle and upper-middle class families. More than 90% of the families are white, and the mean ± SD Hollingshead score12 was 52.4 ± 10.8, which is near the top of social strata IV of the 5-category index. The study was approved by the Institutional Review Board of The Children’s Hospital of Philadelphia.
defined the age of intensive toilet training as the age at which parents asked their child to sit on the toilet or potty more than 3 times per day. Late toilet training was defined as toilet training occurring after 42 months of age, as <1% of children in Brazelton’s study of toilet training in the 1950s were daytime-trained after 42 months of age.1 Children were coded as being frequently constipated if they were treated by the pediatrician for constipation or if parents stated that their child was constipated more than once per week at any followup phone call or about once per week at 2 or more follow-up interviews. Daytime toilet training was scored as completed when parents reported that the child wears underwear during the day and urinates and defecates in the toilet or potty with fewer than 4 urine accidents per week and 2 or fewer episodes of fecal soiling per month. Stool toileting refusal was scored as occurring when a child refused to defecate in the toilet or potty for longer than 1 month after meeting the criteria for daytime toilet training for urine.
Parenting Stress Index Measures and Procedures We assessed the relative contribution of child characteristics, aspects of the care-giving environment, and experiences during toilet training on age at completion of training. At enrollment, child characteristics such as temperament and language development were assessed with the Parenting Stress Index (PSI)13,14 and Receptive-Expressive Emergent Language Scale (REEL),15 respectively. These instruments are described further below. The PSI also allowed assessment of parental stress levels at enrollment. Additional parent and family factors and factors occurring during toilet training were assessed at semistructured interviews that were conducted by telephone every 2 to 3 months until the parents reported that child had completed daytime toilet training at 2 consecutive interviews.
The PSI13,14 is a 120-item rating scale designed for parents of children under 12 years of age. Normal values are available on the basis of administration to more than 2600 individuals. The child domain assesses 4 aspects of the child’s temperament: distractibility/hyperactivity, adaptability, mood, demandingness, and 2 measures that assess the degree to which the child matches the parent expectations and is a source of positive reinforcement for the parent. The parent domain assesses 7 sources of stress, including parent competence, isolation, attachment, health, role restriction, depression, and spouse relationships. For 1- to 2-year-old children the mean (SD) of the child domain stress score in the standardization sample was 98 (20) and the mean for the parent domain stress score was 127 (26).13
Receptive-expressive Emergent Language Scale Follow-up Semistructured Interviews Information obtained at follow-up interviews included whether parents asked the child to sit on the potty in the time since the last interview, and, if yes, how many times per day; whether the child was urinating on the toilet or potty almost always, sometimes, or never, and, if almost always, how many accidents per week the child had; whether the child was having bowel movements on the toilet or potty almost always, sometimes or never, and, if almost always, how many accidents the child had in the past month. Separate questions were asked about hard bowel movements, painful bowel movements, and hiding while having bowel movements. For these symptoms parents were asked if, since the last interview, these symptoms occurred never, once or twice, about once per week, or more than once per week. In addition, we obtained information about child care arrangements and birth of a sibling at each interview. We defined the age of initiation of toilet training as the age at which parents took out a potty-chair and began discussing some aspect of toilet training with the child. We 108
Blum, Taubman, and Nemeth
The REEL15 is a parent report measure designed to assess language development in children from birth to 36 months of age. The REEL provides language scores in 2- to 3month age intervals, which are expressed as developmental quotients (REEL language age/chronological age 3 100). Test-retest reliability over a 3-week interval was 0.7115. National normal values for the REEL are not available, but in three validity studies, children’s mean language ages have been found to be at or slightly above their chronological age.15
Statistics Statistical analyses were performed with the use of the Statistical Package for the Social Sciences (SPSS version 9.0). Means for continuous variables in the late toilet training group were compared with the rest of the sample through the use of the t test for independent variables. Dichotomous variables were compared between late toilet trainers and the rest of the sample by means of the v2 statistic. To adjust for the multiple comparisons, we used a Bonferroni correction in which we considered only P values <.004 to be statistically significant. The Journal of Pediatrics July 2004
Table I. Child and family factors in children who toilet train before and after 42 months of age Training age #42 mo n = 318
> 42 mo n = 60
P value
52.6 ± 10.9 20.6 ± 2.3 28.0 ± 5.1 49.7% 94.4 ± 15.6 108 ± 19 132 ± 20 17.9% 55.3% 26.2% 13.2% 15.2% 66.1%
50.6 ± 10.2 22.3 ± 3.5 31.9 ± 6.6 65% 97.1 ± 14.6 113 ± 22 123 ± 21 56.7% 50.0% 38.5% 41.7% 8.3% 86.7%
> .10 < .001y < .001y .034 > .10 .10 .002y < .001y > .10 .07 < .001y > .10 .001y
Mean Hollingshead score Mean age at initiation of toilet training (mo)* Mean age at initiation of intensive toilet training (mo)*z % Boys* PSI, mean child stress score PSI, mean parent stress score* REEL language quotient* % With stool toileting refusal* % With older sibling* % With younger sibling % Frequently constipated* % In day care throughout study % Hide during training* *Variables included in linear regression models described in Tables II and III. yStatistically significant, P <.004 (Bonferroni adjustment). zBased on 297 subjects who met criteria for intensive toilet training.
P values <.10 but >.004 are discussed as possible trends. A stepwise multiple linear regression procedure was used to investigate the independent contribution of factors found to be important in the above analyses in predicting the age at completion of toilet training. For this analysis, a value of P < .05 was considered to be statistically significant.
RESULTS Children in this sample completed daytime toilet training at a mean of 36.8 ± 6.1 months (range, 22 to 54 months). Sixty of the 378 children (16%) did not complete daytime toilet training until after 42 months and were defined as late toilet trainers. There were no differences between the control group and intervention group for any of the child, family, or initiation of toilet training variables shown in Table I for those who trained by 42 months of age or in those who trained after 42 months (data not shown). Thus, for analyses of the variables shown in Table I, we combined the intervention and control groups. However, the group that trained by 42 months of age did have a higher percentage of individuals in the intervention group than the group that trained after 42 months (54.1% vs 38.3%; P = .034). Thus, we did include membership in the intervention versus control group in the regression model of factors that predict late toilet training. As shown in Table I, parents of later toilet trainers initiated toilet training at an older age than did parents of those who trained earlier; 278 families met our criteria for intensive toilet training at some point during the toilet training process. For these children, later age at initiation of intensive toilet training was also associated with completion of training after 42 months of age. In addition, the later trainers were more likely to have stool toileting refusal, to hide when defecating, to be frequently constipated, and to have a lower language score at 18 months. There was also a possible trend Why is Toilet Training Occurring at Older Ages? A Study of Factors Associated with Later Training
toward the later trainers being more likely to be boys, to have a higher score of the parent domain of the PSI, to hide when defecating before being toilet trained, and to be in the control group. We investigated the ability of these 10 factors (9 noted by asterisks in Table I plus being in the intervention group) to predict age at completion of toilet training in two linear regression models. The first model included all the children in the sample (Table II) and the second model included only those children whose families met the criteria for intensive toilet training (Table III). For the entire sample, the 7 variables shown in Table II explained 33% of the variance in age at completion of training. For those who met the criteria for intensive toilet training, the 6 variables shown in Table III explained 44% of the variance. In both models, 3 of the variables, the occurrence of stool toileting refusal, the occurrence of frequent constipation, and either the age at initiation of toilet training or the age at initiation of intensive toilet training were the strongest predictors. In the model shown in Table II, the 3 variables alone would explain 25% of the variance, and in the model shown in Table III, the 3 variables would explain 39% of the variance in the age at completion of toilet training.
DISCUSSION For many children today, toilet training is being completed much later than in the past. We found that three factors consistently explained a significant portion of the variance in age at completion of toilet training: age at initiation of toilet training (or intensive toilet training), the occurrence of stool toileting refusal, and the occurrence of frequent constipation. The relatively large effect of these three variables in our study, combined with epidemiologic data from other sources, suggests that these variables may contribute to 109
Table II. Linear regression model predicting age at completion of toilet training for all children in sample Factors*
Standardized regression coefficient
P value
Overall P value
Overall R2
Stool toileting refusal Age initiation of toilet training Frequently constipated Sex Hides during training Has younger sibling REEL language quotient
0.342 0.173 0.170 0.132 0.148 0.135 0.116
< .001 < .001 < .001 .004 .001 .002 .011
< .001
0.329
*Age at initiation of intensive training was not included in this model because some families never reported meeting the criteria for intensive toilet training.
Table III. Linear regression model predicting age at completion of toilet training for 278 children who met criteria for intensive toilet training Factor
Standardized regression coefficient
P value
Overall P value
Overall R2
Age initiation intensive toilet training Stool toileting refusal Frequently constipated Has younger sibling Hides during training In control group
0.414 0.359 0.175 0.133 0.128 0.094
< .001 < .001 < .001 .003 .005 .040
< .001
0.444
the trend toward later completion of toilet training that has been seen over the last 30 to 50 years. For example, studies that have investigated trends in the age at initiation of toilet training suggest that toilet training is being initiated later than it was 30 years ago.8,16,17 In a survey of parents in Iowa in 1970, >95% expected to begin toilet training before 24 months of age.18 In a survey of parents in Minnesota in 1985, 73% began training before 29 months of age,2 and in a 1996 survey of parents from the greater Milwaukee metropolitan area, toilet training had not started in 35% of 30- to 34-month-old children.3 The reasons that parents now initiate training at older ages are not known. Berk and Friman16 have suggested that it is related to widespread dissemination of information, suggesting that early training does not lead to earlier completion of training and the ready availability of disposable diapers. It has also been suggested that parents may have difficulty judging when children are ready to train.11 For example, a recent study of when children achieved 11 different readiness skills found that the earliest achieved readiness skill (eg, stays bowel movement–free overnight) occurred at a median of 22 months in girls and almost 25 months in boys.19 The skill that was achieved the latest (eg, pulls training pants or underwear up by oneself) was not achieved until a median of 29.5 months in girls and 33.5 months in boys.19 Given the large age range over which these skills occur, it would not be surprising if parents have a difficult time judging when their child is ready to toilet train or alternatively decided to wait until the child has achieved all the readiness skills. 110
Blum, Taubman, and Nemeth
Our study supports earlier reports that stool toileting refusal is associated with delayed toilet training as more than half of the children who did not train until after 42 months had stool toileting refusal.4,20 Stool toileting refusal has been associated with constipation,20,21 but in our study’s multiple regression model, both frequent constipation and stool toileting refusal made an independent contribution to predicting age at completion of toilet training. Although changes in these factors over time are not well studied, some data would suggest that these factors may also contribute to the trend toward later training. For example, Brazelton found that >90% of children trained for bowel first or bowel and bladder at the same time.1 A longitudinal study of healthy Swiss children from 1955 to 1976 found that >95% of 3-yearolds were reported to be trained for bowel movements, whereas <2% had daytime bladder control and were not trained for bowel movements.22 Not all of the children who obtained bladder control before achieving toilet training for bowel movements would meet our criteria for stool toileting refusal, but it is clear that those who train at the same time or train for bowel movements first would not. Thus, the maximum possible incidence of stool toileting refusal in previous studies is 2% to 10%, compared with the 20% to 25% incidence that we have found in this and another recent study.4 The reasons for the increase in this specific type of resistance to toilet training are not known, but it appears to be increasing and contributing significantly to the trend toward later completion of toilet training. Trends related to constipation are difficult to evaluate because of huge differences in the incidence, based on the The Journal of Pediatrics July 2004
definition and method of reporting. However, Sonnenberg and Koch23 found that although the overall rate of physician visits for constipation was unchanged between 1958 and 1986, there was a 2-fold increase in physician visits for constipation in patients 0 to 9 years of age, suggesting that constipation in the pediatric age group is increasing. Others have also reported very high rates of constipation in children of toilet training age.24 Additional factors that we or others have found to be associated with later toilet training such as male sex, white race, not living in a single-parent family, and some temperament factors are either very unlikely to have changed significantly in the past several years or have not changed in the direction that would explain the trend toward later training. For example, there are more single-parent families today than 50 years ago, but children in single-parent families have been found to train earlier.3 The results in this study should be considered in the context of the following limitations. The results apply to a primarily white, suburban, upper middle-class population. Because of the homogeneity of the sample, the effect of race and being a single parent could not be investigated in this study, and the factors influencing toilet training are likely to be different in other populations.25,26 All of the information in this study was collected by parent report. We attempted to minimize recall bias by interviewing parents every 2 to 3 months, but our results were still dependent on the parent’s recall and report of their toilet training practices and results. Despite these limitations, our study identifies three factors that are highly associated with an older age at completion of toilet training. In addition, there is evidence to suggest these three factors, age at initiation of toilet training, the development of stool toileting refusal, and constipation, have changed over the last 30 to 50 years in ways that could contribute to the trend toward later training. Further studies will be needed to determine whether interventions targeting these variables result in a decreased incidence of late toilet training.
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Why is Toilet Training Occurring at Older Ages? A Study of Factors Associated with Later Training
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